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Best Saltwater Urchins for Beginners – Awesome & Unique Janitors!

Are you looking for something a bit different to add to your aquarium? Have a problem with algae, and are wanting an algae grazer? Then look no further as you have stumbled across the perfect article for you!

Sea urchins are invertebrates, with a soft body and a hard exoskeleton usually covered in spines. Even though these crawling critters can sense light and dark, they will mainly use their sense of smell to navigate around your aquarium, and even though they appear to be slow, they soon get around!

The Best Urchins For a Beginner Saltwater Aquarium Are:

  • Pincushion Urchin
  • Long-Spined Urchin
  • Short-Spine Urchin
  • Blue Tuxedo Urchin

Sea urchins will scavenge the aquarium for unwanted algae and detritus that builds up in your tank, often carrying things and burying themselves in the substrate. This means they like to overturn rocks, which can damage other aquarium residents (especially corals), the tank, or even themselves, therefore extra care is needed when keeping urchins.

Always be careful when handling them as they can puncture the skin – their spines can break into tiny pieces once inside your skin, making them difficult to remove and painful! Trust Me! The Long-Spined Urchin is the usual culprit!

Urchins are sensitive to water changes and cannot tolerate copper-based medication, so making sure their water parameters are within range is really important!

For success with Urchins, your first priority is to keep your water parameters in the following ranges:

  • Temperature: 22.2 – 25.5°C or 72 – 78°F
  • Salinity: 30.5 – 33.2 ppt or 1.023 – 1.025sg
  • pH: 8.1 – 8.4
  • Alkalinity: 8 – 12 dKH

Beginner Tip: Signs of Poor Water Quality is Spine Loss

My Top Beginner Sea Urchins:

As a beginner, it can be overwhelming what urchin(s) to start with. You will want ones that are peaceful, hardy, and easy to care for to ensure you have the greatest success in keeping them. If you have a big enough tank (over 100 gal), you can have more than one – they are solitary animals but do not seem to be aggressive towards each other.

They are scavengers so I would ensure your aquarium has lots of algae for them to feed on. I would recommend you wait at least 6 months after your aquarium cycle has finished before adding your first urchin.

Below is my Top Urchins you can start with that are great for beginners!

Pincushion Urchin

(Lytechinus variegatus)

  • Max. Size: 8”
  • Diet: Herbivore & Omnivore
  • Care Level: Easy
  • Temperament: Peaceful
  • Min. Tank Size: 20 Gallons
  • Priced from: $10.00

These nocturnal urchins, which range in colors from red, white, and blue, are easy to care for, peaceful, and super affordable – which is why they are my favorite for beginners!

Stay away from the Purple Pincushion Urchin as these are not beginner-friendly!

They love hiding, so you will want plenty of hiding spots for them during the day. When they come out at night, they can be seen moving around searching for algae to graze on – particularly live rock. If you do decide to buy a pincushion urchin, make sure that any rock formations are stable, so your urchin does not get stuck between them. 

As you can see in the photo, they love to pick up shells, rock rubble, and bits of coral on their spines that they use for camouflage. It can be quite amusing to see how they decorate themselves!

Long-Spined Urchin

(Diadema setosum)

Source: Matt Kieffer
  • Max. Size: 10”
  • Diet: Herbivore
  • Care Level: Easy
  • Temperament: Peaceful
  • Min. Tank Size: 25 Gallons
  • Priced from: $30.00

Also known as the Black Long-Spined Sea Urchin, this one gets its name from the long black spines that are mildly venomous covering its body – no need to worry, they do not threaten us humans, they just sting a little!

They are easily identified by their bright orange anus in the center of its mass of spines. – Officially known as the Periproctal Cone for any science nerds out there like myself!

These guys grow a lot larger than other sea urchins, so ensure you have enough space for them to move around. These guys will take up a lot of room in a nano aquarium so those size tanks are best avoided.

One great thing about these urchins is that they have a symbiotic relationship with Bangai Cardinalfish (Pterapogon kauderni) who will ‘Hang Out’ in the urchins’ spines for protection.

Short-Spined Urchin

(Echinometra sp.)

  • Max. Size: 3”
  • Diet: Herbivore
  • Care Level: Easy
  • Temperament: Peaceful
  • Min. Tank Size: 20 Gallons
  • Priced from: $12.00

Also called the Rock Burrowing Urchin, these round-bodied urchins have hundreds of white/red/orange spines with long tube feet to move around your aquarium.

They get the name ‘Collector Urchin’ as they like to camouflage themselves by covering their body with seaweed and small rocks therefore you will want plenty of live rock for them to graze on and stable rock formations for hiding.

Their diet should also include dried seaweed/nori, especially if your aquarium is still unmatured and relatively algae-free.

Blue Tuxedo Urchin

(Mespilia globulus)

  • Max. Size: 3”
  • Diet: Herbivore
  • Care Level: Easy
  • Temperament: Peaceful
  • Min. Tank Size: 20 Gallons
  • Priced from: $33.00

Also known as the globe urchin – these are very peaceful, easy to care for, and do not grow super big making them suitable for most aquariums. Tuxedo urchins are reef safe and hardy, making them easy to care for, and perfect for beginners.

Tuxedo urchins are covered in hundreds of sort uniform spines that are sharp and can puncture human skin, so handle these guys with care!

As they do not grow too big, they are one of the less ‘clumsy’ ones so will not be knocking over everything in your aquarium – but they are keen scavengers, so will still move small objects around as they search for food.

Tuxedo urchins do not tolerate fluctuations and high levels of nitrate, so it is recommended you supplement your tank and take extra care when acclimatizing them into their new environment.

They are also very sensitive when transporting, so drive carefully with these urchins on board!

How Do You Care For Sea Urchins?

Firstly, you need to consider space for them as they like to slowly move around and also contribute to the bio-load in your saltwater tank. They generally like the same temperature and salinity levels at their tank mates, but you should always research the specific needs of the species you wish to keep.

Sea urchins love to move around and can be super clumsy! They will knock over things in their way. Make sure you have a very sturdy set up to avoid fish getting injured and trapped underneath the urchins.

Who Can Sea Urchins Share A Tank With?

When selecting the right urchin for your aquarium, you must consider compatibility. They should not be sharing a tank with aggressive predators such as puffers, triggerfish, and octopus. These feisty guys will tear off their spines and break their shells so they can eat them.

You should also avoid small predatory fish that will swim between the urchin’s spines injuring themselves. As long as you have enough space and food for them, you can have more than one sea urchin as they are generally very peaceful creatures.

What Do You Feed Sea Urchins?

Most of these spiny critters enjoy munching on algae, but some prefer something a bit ‘meaty’ from time to time. If you are specifically looking for an algae cleaner, then the Tuxedo Urchins are a great choice!

Make sure you do not overfeed your urchins as a build-up of uneaten foods leads to harmful toxins in the water like ammonia – this will not only affect your urchins but their tank buddies too!

Urchins To Avoid & Why!

Some urchins are not compatible with reef fish or corals so, which urchins should you avoid?

Below is a quick summary of 3 urchins you want to avoid and why!

Slate Pencil Urchin

(Heterocentrotus mamillatus)

  • Not easy to care for
  • Not reef compatible for corals

Purple Short Spine Pincushion Urchin

(Pseudoboletia sp.)

  • Semi-aggressive
  • Must be added with caution with other reef fish

Long Spine Banded Urchin

(Echinothrix calamaris)

  • Not easy to care for
  • Venomous

To Finish

By now you should have a basic understanding of what sea urchins are, what ones are beginner-friendly, ones you should avoid, and how to care for them in your saltwater aquarium.


  • Perform regular water changes.
  • Try not to disturb them & damage their spines when cleaning around them.
  • Some species are not compatible with all reef fish – do your research before buying!
  • They should be kept where there are lots of algae to graze on, otherwise, they will starve – but do not overfeed them.

Further Reading

If you found this article helpful, I highly recommend you check out these ones too:

What is a Closed-Loop Reef Tank?

I remember having this same question many, many years ago about what was closed-loop reef tank? And if you are here, you probably have a bunch of questions like what they are too? What is their purpose? Are they worth it? And are you missing out on something by not using a closed-loop system?

A closed-loop reef tank is a saltwater aquarium that has been fitted with a piped-in water circulation system. Closed-loops create high-flow water movement necessary for fish & coral health while keeping the aquarium free of obtrusive pumps & equipment. They are best suited to large aquariums.

If you want to learn more about closed-loop systems, continue reading below, where I go into more detail about everything you need to know.

What Is Considered a Closed Loop Reef Tank?

Closed-loop systems are piped circuits in which the aquarium water is circulated throughout the system without it being exposed to the outside environment. With closed-loop reef tanks, all inlets and outlets are constantly submerged and comprise one continuous loop.

Rossco’s Closed-Loop System on Aquarium Forums

The aquarium water is pulled through one or several intakes by an externally mounted water circulation pump and then is pumped back into the tank through one or several nozzles.

Usually, a significantly greater water flow can be generated with a closed-loop system compared to using individual powerheads and wavemakers, especially on long or large aquariums.

In comparison, the most common reef aquarium setup using a sump is considered an open-loop system, because the water that is pumped through the system is exposed to the outside atmosphere when it reaches the sump.

Aquarium Sump Operation
An Typical Open-Loop Tank & Sump Setup

That being said, closed-loop systems and open-loop systems shouldn’t be viewed as systems that cannot coexist. In fact, many aquarists use them together—the closed-loop system provides water flow, and the open-loop system the filtration.

An Open & Closed-Loop Reef Tank Setup

Why Are Closed Loop Reef Tanks Used?

Closed loop systems are used mainly for creating water flow within the main display aquarium.

To a certain degree, closed-loop systems can be considered the old-school way of providing water flow in larger tanks because back then, we didn’t have the powerful wavemaker pumps we have today.

Closed-loop systems are mainly used on large and usually custom-built reef tanks because the holes have to be pre-drilled before the glass gets tempered. Because of this most closed-loop systems will be found on the larger 100 to +800 gallon reef tanks.

Closed-loop systems are usually either located underneath or behind the tank. Placing the closed-loop pipework and circulation pump under the tank is preferred because it is more aesthetically pleasing, allows the tank to hug the rear wall a little more tightly, and generates good water flow that will not allow the detritus to settle down.

Closed-loop reef tanks are not as common as they used to be used because they require a lot more work and cost to install but, in return, allow for clutter-free and smoother running display tanks. It all comes down to the personal preference and budget of the aquarium owner at the time they install the tank and filtration.

Advantages and Disadvantages of Closed Reef Tanks Systems

Clutter-Free Display Tanks

Most people don’t really enjoy the sight of powerheads, especially me!. Even though some powerheads can be hidden within artificial rocks, or behind the aquascape, they are still not very pretty to look at. If you can hide the pump, you usually then have the cables to look at!

To me, a reef aquarium should display the beauty of the living world within it with as few mechanical devices on show as possible!

Since you do not need to use powerheads and wavemakers with a closed-loop system, this allows you to keep the clutter in your display tank to an absolute minimum.

Maintenance and Care

The routine maintenance and care on closed-loop systems, if properly set up, is very easy to do. Ball valves must be placed before and after the circulation pump(s), allowing for easier mounting, dismounting, and servicing.

Ball valves should also be turned weekly to prevent seizure over time! One owner I knew did not do this, then when his closed-loop pump died he had a heck of a time unseizing that valve!


Leaks are possible with any type of aquarium, but as long as the bulkheads and the piping are installed correctly, there shouldn’t be any leaks, this is the same no matter the type of system installed.

If you turn the power off on a closed-loop reef tank, the water level will not change—only the water flow will stop.

In comparison, in an open-loop reef tank, not only will the water flow stop, but the water level will also drop until it goes below the overflow. This means that a sump flood can happen if setup improperly because it is an open-loop system.

Water Flow

Depending on what corals and type of fish you have in your tank, you will need different amounts of water flow—which can easily be achieved with a closed-loop system. By using nozzles and valves you can direct and control the flow in many parts of the tank.

This means that you do need powerheads. If the closed-loop system is set up properly, you can generate more than enough water flow to keep an SPS and LPS reef vibrant and healthy, even in the largest aquariums!

However, alternating the flow can pose some difficulties compared to using powerheads, which you can place and direct in any direction you see fit. This is why owners often install flow diverters on closed-loop systems, like the ones from Oceans Motions and SCWD, to keep the water flow more natural and randomized.

How An Oceans Motion Works:

What The Water Flow Does:

Noise Levels

Although most powerheads are fairly quiet, it is not uncommon for them to make strange noises, especially when they are ramping up and down in flow. Keeping that in mind, a closed-loop system should normally be quieter, with just a constant hum from the circulating pump.

If your aquarium is going in a noise sensitive area then you are best advised to join your local reefing club and visit tanks that run both closed loop systems and ones that just run powerheads to see for yourself.

There is no getting away from noise sometimes. Although the new wavemakers are incredibly quite, so to are the new circulation pumps.


The number of holes drilled can vary between two to ten or more in some instances, with the most common being between four to six holes—two drains and two to four returns. The drains are typically 1.5 inches in diameter, and the returns 1 inch. Drilling holes with a larger diameter is often avoided for safety reasons.

Drilling the tank is one of the things that should be considered carefully. Once you drill the tank, you cannot go back; it’s not reversible, and mistakes can be costly.

Drilling a tank is easy, but drilling should be done only on untempered glass because drilling tempered glass will shatter it, with explosive power! This is why most closed-loop systems are designed before the tank is manufactured as almost all bottom panes in an aquarium are tempered for strength.

It is possible to make a closed-loop without drilling but that usually takes away all the aesthetical advantages and appeal closed-loops can offer. Usually, the pipework is going to be a little more complicated to set up, and it will have to go up and over the top of the tank, so it is not a pretty sight to look at, but it does work. With careful cabinet construction, you can hide a good portion of the pipework within the canopy, only seeing the nozzles under the waterline.

There are many great DIY examples out there, but there are also some horrible one too!

A Single Point of Failure

The quality and type of pump you will be using is extremely important! This is not the place to cheap out on!

You want to use a high-quality pump that can run 24/7 for years without failing because if it fails, it will prevent the whole system from working. Losing your only source of flow can be fatal for your coral.

Because of this, many closed-loop owners will have a spare identical pump all plumbed and ready to be swapped out at a moment’s notice.


It is arguable whether or not a closed-loop will be more cost-effective in terms of providing water flow compared to using powerheads.

A less powerful powerhead is still viable on smaller aquariums, but on larger tanks where many powerheads may be necessary, installing a closed-loop can potentially be cheaper. It’s a matter of calculating the wattage used.

The more powerheads you run, the more watts are consumed. Compare that to the single wattage of the closed-loop’s circulating pump and you could be saving quite a lot of money running just the one pump.

The other cost to consider is the initial setup. Having the tank drilled, pipework installed, a circulating pump, spare pump, and maybe a flow diverter could run you around $1000-1500, however, just a single powerhead/wavemaker can run you $300-700 and depending on how many you will require may make a closed-loop cheaper.

Is a Closed Loop Reef Tank Worth It?

In my opinion, closed-loops still have their place. They are neither obsolete nor a relic of the past and they are arguably one of the best ways to keep a clutter-free tank while providing optimal levels of water flow, especially if the aquarium is long or large. If properly set up and designed, you will not see any pipes or power cables!

But powerheads have improved in quality and performance over the years to the point where they—although not visually appealing—can be considered a good alternative since they are super easy to install and can provide tremendous amount of flow, especially the Gyres!

For More Information on Wavemakers & Gyres, See them Here at Marine Depot

The reality is not many owners will be comfortable with or willing to drill multiple holes in the rear panels (bottom panels are tempered remember) of their tanks to set up a closed-loop system. As a result, closed-loop systems have come a little out of favor and are not so commonly used today. This makes closed-loop systems more of a hassle to initially set up, but they are still worth considering, nonetheless, especially if you love to DIY!

To Finish

Closed-Loop Systems are a great way to provide tremendous and sometimes alternating flow to a reef aquarium. By using a pump, a few drilled holes and some plumbing you can really create a stunning aquarium with zero equipment in sight.

Primarily used on larger aquariums where the installation of multiple powerheads would be required, a closed-loop system can make aesthetic and financial sense. But the cost and design of a custom aquarium can then make a very unattractive option to most reef tank owners.

For small aquariums, powerheads and wavemakers are the best route. For long and large aquariums, the Closed-Loop is a great alternative.

Further Reading

If you found this article helpful, please take a read of some of my others:

How Much Aquarium Salt Per Gallon? It’s Really Simple To Do!

For beginner aquarists to saltwater one of the most daunting tasks is correctly making the saltwater itself. The thought of getting it wrong and everything dying fills many beginners with dread, but it is actually a very straightforward process.

Aquarium saltwater mixes at a ratio of 1/2 cup or 135g of purposely engineered aquarium salt granules for every gallon of fresh water. This will ensure the salinity of 1.025 or 35ppt which is perfect for a home aquarium.

Once you have read this article you will have no fears about what you need and how to mix the salt and water to give you the perfect mix ready for addition to your new shiny aquarium. It is very straight forward and you will become a water change master in no time!

Before you begin mixing, you need to ensure you have the right kind of salt for the aquarium. Regular table salt will not do!

What Kind of Salt Mix Should You Use in an Aquarium?

Salt mixes for home aquariums are highly engineered to provide optimal water conditions for fish, coral, and invertebrates. It is not only the salinity that they provide but dozens of trace elements like Calcium, Magnesium, Carbonate, Strontium that the invertebrates use as building blocks for their skeletons.

There are many great brands that have decades of pedigree behind them so picking a salt is easy. The salt that I have personally been using for over a decade is Reef Crystals from Instant Ocean.(Amazon Link)

Each brand of salt can mix may be mixed to slightly different quantities so be sure to always read the manufacturer’s information when starting a new brand of salt. Some mixes are specially made for fish-only aquariums, whereas Reef Crystals is aimed at aquariums with large coral populations. No matter which salt mix you pick, they will all work, the ones with more trace elements for corals are just a little more expensive!

Reef Crystals Aquarium Salt
Reef Crystals Aquarium Salt

When selecting a salt mix stay away from freshwater aquarium salt which is used by freshwater aquarists to recreate brackish water conditions. Although these salt mixes will work to create the correct salinity they do not contain the trace elements like sodium, chloride, sulfate, and magnesium necessary for marine organisms to thrive.

TBR Recommends

Find a Great Selection of Aquarium Salt Mixes at Marine Depot

How Much Salt Mix Should You Use in an Aquarium?

Each manufacturer is slightly different for what is recommended to achieve a salinity or specific gravity of around the recommended 1.025sg or 35ppt (Parts Per Thousand). This figure is also based on the water temperature being at 25°C/77°F.

Most saltwater aquariums run at a temperature of around 78°F (25.5°C) to 80°F (26.6°C) so the salt mixes will have to be measure and tweaked to ensure 1.025sg at your selected temperature – I run my aquarium at 78°F

Some brands will give you a volume to measure, whereas other brands will give you a weight to measure out. Whichever brand you pick, just follow the instructions printed on the side of the packaging. Just measure out the recommended amount of salt granules and add it to the mixing container with freshwater. A pump is then used to mix it and a heater to warm it.

This then turns your bucket of water into saltwater!

Here are some of the best salt mixes for beginners and how each manufacturer recommends they are measured to achieve a salinity of 1.025 at 25°C/77°F:

Salt BrandMixing Recommendation
Instant Ocean1/2 Cup per 1 U.S. Gallon
Red Sea Salt136g per 1 U.S. Gallon
Tropic Marin Classic Salt1/2 Cup per 1 U.S. Gallon
Neomarine Salt Mix134g per 1 U.S. Gallon

How To Correctly Mix Aquarium Salt

If this is going to be the first time you have mixed saltwater for your new aquarium there is a fairly simple process that you can use, but you will need to gather the following items before you start:

(All Links to Marine Depot for Reference)

Before you begin be sure to place down towels, salt granules or saltwater can stain carpets and flooring!

Step 1

If you have a brand new tank you can do your mixing in the tank but do not add the live sand or live rock at this point. The freshwater will kill all living organisms and beneficial bacteria on them.

Do not use any detergent when rinsing your new bucket/trashcan, just warm water and a cloth to wipe away manufacturing oils.

Food grade containers are recommended because low-grade plastic can leach phosphate into the water over time.

If you wish to do your aquascape and insert the sand first, then mix your water in the trashcan/bucket.

Step 2

Fill the tank or container with water. If you can, get yourself an RO/DI water filter (See Further Reading section at the end) to help prevent water quality issues for the life of your aquarium! If not, use the Prime Decholrintor solution to treat the tap water as per its dosage instructions.

If you are mixing in the aquarium, be sure to only fill to around 70% of the volume of the aquarium to leave room for rock and sand displacement when you add them later.

Step 3

Turn on the heater and pump to circulate and bring the water up to 78°F.

Step 4

Once up to temperature, begin to add the salt following the manufacturer’s recommended dosage of around 1/2 cup or 135g per US gallon.

Step 5

Allow the water pump to mix the water and salt solution. Don’t worry if you see any sand-like residue or cloudy water, that is normal. Ensure all salt granules get dissolved.

Step 6

After around 30 minutes take a salinity reading. Add water if the salinity is too high, add more salt if the salinity is too low.

Step 7

Allow mixing for several hours to several days to get the salinity content dead on. Repeat Step 6 as needed.

Step 8

If you decided to add your rock and sand later, now is the time to do it. Slowly add your rock to create your aquascape, then add the sand! Adding rocks on top of sand can cause them to topple when burrowing critters get added to your tank. Rock on glass is fine, just be slow!

Step 9

Mix some more saltwater in your bucket/trashcan and add it to the aquarium to bring up the water level to the correct operating height once all the rock and sand is in. Be sure to fill enough for the sump/filters.

Step 10

Your tank will go cloudy for several days, allow the filters to run and pull out the suspended debris.

Your aquarium is now full and you can begin the fun of cycling the tank ready for it to become a full saltwater reef tank!

For lots more detailed articles on water changes and cycling your tank be sure to check out the Further Reading section at the end of this article.

How Do You Measure the Salinity of a Saltwater Mix?

The unit of measure for salinity is known as specific gravity or sg. The ideal salinity for a home aquarium is 1.025sg but the tolerable range is 1.021sg to 1.026sg depending on what livestock you have. Pure water has a specific gravity of 1sg. If your saltwater mix measures 1.025sg, it means that it is 1.025x denser than pure water.

Fish only aquariums can be at the lower end of the scale of around 1.021sg, whereas SPS corals prefer to be up at around 1.025sg. The lower the salinity, the less salt mix you use so it becomes cheaper when doing water changes.

My recommendation is that if you wish to only keep fish, then mix your water to 1.021sg, if you plan on keeping invertebrates and corals then begin your aquarium at 1.025sg.

To be able to measure the amount of salt content in your water there are three options available to the aquarist:

  1. A Hydrometer – Cheap, but hard to read
  2. A Refractometer – ost Used Option
  3. An Electronic Salinity Meter – Highly accurate but xxpensive

Let’s go into a brief introduction of each of these measuring instruments:


Glass Hydrometer & Thermometer

Hydrometers measure specific gravity by using the concept of buoyancy. You float the hydrometer on the surface of the water and it will give you the sg reading based on where the water level touches its measuring stem. Reading the stem can be quite difficult.



Refractometers determine salinity by measuring the light refraction caused by the salt in the water and self-correct for temperature. You place a drop of water on the prism and view the result through the eyepiece. They are fast to use and can be easily calibrated with a simple solution.

A Refractometer is what I recommend you use. For around $35 it will last you forever (mine is 15 years old and still works perfectly!) and give you highly accurate results within 30 seconds of taking it out of the box!
You can find one Here at Marine Depot

Electronic Salinity Meters

Pinpoint Salinity Meter
Pinpoint Salinity Meter

Salinity meters use a sensor to measure the salt content in the water. They are very simple to use and give an easy-to-read numerical value. They are easily calibrated using a test solution.

For lots more detailed information about measuring salinity please see our article in the further reading section below.

To Finish

In order to create artificial saltwater, use as pure a water source as you can and a recognized aquarium salt mix.

Use the recommended dosage of around 1/2 cup or 135g per gallon, but be sure to follow the specific instructions provided by the salt manufacturer to achieve a salinity reading of around 1.025sg at 78°F for your new aquarium. For partial water changes, salinity and temperature levels must match that of the existing tank water.

Further Reading

Before you get too far unto your aquarium journey I recommend the following articles to help you progress seamlessly:

Best Saltwater Shrimp for Beginners: These Are Great Characters!

Shrimp are a beautiful and entertaining addition to your saltwater tank and by having just a couple of these characters in your tank will help to dramatically increase your viewing pleasure! Most of the shrimp are super easy to care for and this is why many hobbyists love to have them in their aquarium, I know I do!

Not only do shrimp add some nice visual diversity they also work as fantastic members to your clean-up-crew. Being mostly scavengers shrimp will set up home in their favorite spot in the tank and then wander looking for food.

By helping to keep uneaten food, fish waste, and dead animal matter under control the shrimp help to maintain higher water quality which is a win-win for everyone!

Some the Best Saltwater Shrimp for Beginners’ Aquariums Are:

  • Harlequin Shrimp 
  • Peppermint Shrimp 
  • Camel Shrimp 
  • Scarlet/Skunk Cleaner Shrimp 
  • Blood Red Fire Shrimp 
  • Sexy Anemone Shrimp
  • Banded Coral Shrimp
  • Saron Shrimp
  • Bumblebee Shrimp

Harlequin Shrimp

(Hymenocera elegans)

Prices Range From $50

This shrimp is from the Pacific and Indian Oceans and belongs to the Palaemonid family and is a very fine choice for your saltwater aquarium setup.

They have an incredibly bewitching appearance with their white or cream color bodies and purple, blue or red spots making them look like a work of art, hence it is also called painted shrimp.

This shrimp is a scavenger and can eat anything but they absolutely love eating starfish. Now, this shrimp is not a good option if you have or wish to keep a starfish, but it will devour any Asterina Starfish, which is a coral parasite, thus protecting your corals.

They are shy when coming into the new aquarium and will take their time adjusting to it, so don’t be afraid if you add it and then don’t see it for a while! Eventually, you can usually find them hiding in a rock cave for which they call home, and use it for shelter and protection.

Although they are friendly with other tank mates, they can be aggressive towards their own species, so it is not advisable to keep them in groups but better keep alone, or in a mated pair.

They can grow to 2 inches so can easily be kept in a 10-gallon tank.

Peppermint Shrimp

(Lysmata wurdemanni complex) 


Around $10

This little beauty belongs to the family Hippolytidae is often called veined shrimp, Caribbean cleaner shrimp, Candy Cane Shrimp, or Sweeper shrimp.

They are very useful for keeping in the aquarium as they love to hunt the dreaded pest known as Aiptasia; the glass anemones. These anemones reproduce at high rates, overrun real-estate for coral and can sting fish in the tank.

This shrimp is mostly nocturnal, staying hidden in the rocks and cervices to only come out at feeding time, but over time will become used to your dayly aquarium life and start to swim freely searching for food. Their bodies are brightly colored, somewhat translucid with pink to red stripes.

It is a carnivore and will become a major part of your clean-up-crew. They will eat leftover organic matter, dead fish tissue, and detritus to help clean the tank.

This shrimp is usually civilized and pleasant with other tank members but be mindful because it can be hostile towards its own species so have one in a small tank or a few in the large tank.

They can grow up to 2 inches in size and again perfect for Nano Tanks.

Camel Shrimp

(Rhynchocinetes uritai)

Source: Seaotaro

Around $15

This shrimp is native to Australia, East Pacific, East Indian Ocean, Indonesia, and central/west Pacific and belongs to Rhynchocinetidae family.

They are named Camel shrimp because of their distinctive hump just like a camel. They are also called hinge beak shrimp because of containing a beak or rostrum which most of the time pointed skywards. Other names of this shrimp are candy shrimp and dancing shrimp. They have large eyes which helps them move around in a low-light environment as they are mainly a nocturnal member of the tank.

Their bodies contain very vibrant, bright cherry-red colored stripes so sometimes they can be mistaken for peppermint shrimp, but their hump easily differentiates between both of them.

This shrimp is a very good tank cleaner as it eats debris and other waste matter. This shrimp is very friendly and amicable with other fish, invertebrates, and their own species, so you can easily put them as a colony of 4 to 6 individuals in a large tank.

Due to its quiet and calm nature, it can be a target for predators so pay attention to any fish which can be known to prey on shrimp, especially Hawkfish.

In the aquarium, their diet is mostly omnivorous so you should feed them with diverse foods like vitamin-rich flakes, frozen plankton, crustacean larvae, clams, and mussels if your tank is fairly unmatured.

Due to all these mentioned factors, they can be slightly difficult to care for when your aquarium is new, but once matured and lots of algae and livestock have been in for a year they will do great.

They can grow a maximum of 2 inches and you can put one of them in a 10-gallon tank.

Scarlet Cleaner Shrimp

(Lysmata amboinensis)

Source: Chris Moody

From Around $35

This shrimp is from the Indo-pacific region and belongs to the Hippolytidae family. It is one of the most famous and graceful creatures you will find in many reef aquariums.

Its body color is yellow with striking red and white stripes with very long white antenna that you will usually see sticking out of a rock cave, long before you see the shrimp itself!

This shrimp gets its name by setting up a station on a piece of rock and gives grooming assistance to the fish by cleaning their bodies, fins, and even mouth. It eats dead tissue and any parasites it can find and in exchange for this service, fish do not try to prey upon the shrimp, which makes this relationship a symbiotic one.

My Yellow Tang is one of my Cleaner Shrimps favorite customers!

Any predatory saltwater fish is not compatible with this shrimp so avoid keeping both of them in the same aquarium. It is an omnivore and can eat any type of food, sometimes it can even munch on corals so keep an eye out for their behavior. They will swim and climb on you when your hands are in the tank and it’s interesting to feel them picking away at your nail cuticles!

They can grow to 2 inches and again, perfect for any size aquarium.

Blood Red Fire Shrimp

(Lysmata debelius)

Source: Eacesar

Starting Around $45

Originating from Indo-pacific regions blood-red fire shrimp is by far the most exquisite, elegant, and popular of all shrimp, but you can pay a hefty price for one!

It is also known as Fire Shrimp, Blood Shrimp, and Scarlet Shrimp because of its blood-red colors and long antennae. It is effortless to keep them because they don’t require any special requirements in your tank only that; it doesn’t like intense lighting so you will usually find them under a ledge or in a cave.

To help with this, if you set up a cave facing the front of the tank when you layout your aquascape, you can ensure this beauty is seen instead of hiding around the back!

They are usually calm and pleasant with other tank mates (providing they don’t encroach in its territory) but can get intolerant towards their own species. They are great to be kept in pairs in a tank of +55 gallons.

Be sure to house these without Marine Bettas, Hawkfish, and bigger fish that can eat them without a second thought.
This shrimp is part of the cleaning and scavenger crew and lurks at the bottom of the tank searching for meaty chunks and leftover food.

When fully accustom to your tank it will also establish a cleaning site where it gives special cleaning services clearing away parasites and dead tissues from fish fins and gills.

They can grow up to 3 inches with only one housed in a tank of 20g or more.

Sexy Anemone Shrimp

(Thor amboinensis)

Source: Brian Low

From Around $15

This shrimp owns the title of being among the cutest of all invertebrates having a very faraway enchanting look with their reddish-brown spots and exotic behavior. They are called sexy shrimp because of their walking and waving or their abdomens.

They originate from the indo-pacific region and belongs to the Hippolytidae family. It usually prefers living among anemone tentacles in the wild, but in the aquarium, you will see it sitting on rock outcroppings or rummaging through the sandbed in search of food.

This shrimp has a symbiotic relationship with anemone’s, especially Carpet Anemones because they provide it protection and in return, it assists them in cleaning.

This shrimp is an omnivore and will scavenge for any meaty morsel or can be seen picking away at bits of algae it finds. Besides being beautiful, it also shows friendly behavior with other tank mates so, to keep them happy and healthy you should put it in groups and feed them a diverse diet consisting of plankton, meat, and frozen bits.

Because of their micro size, they are best suited to nano and pico aquariums to not only keep it safe from hungry mouths but placing these in a large aquarium may be the last time you ever see it! One other thing to keep in mind is that this shrimp is very docile so be sure to place it in a peaceful aquarium for the greatest chances of success.

They can grow to 1-1/2 inches in size.

Banded Coral Shrimp

(Stenopus hispidus)

Source: Steve Childs

Starting Around $15

This beautiful red, white, and blue banded creature with its long antennae and pinchers belong to the family Stenopodidae which are predominantly scattered throughout the Indonesian ocean.

It can be also found under the names of a Banded Cleaner, Boxing or Coral Shrimp. It usually keeps its pinchers erect giving the impression that it is ready for a fight, hence the name Boxing shrimp and It has an active personality as it is seen scurrying around the tank searching for food.

My shrimp, along with most of the banded shrimp like to be found dangling upside down in their favorite cave or under a rock so make sure you have a lot of live rock with and hiding places in your tank for this beauty. Another reason to build in a hiding place you can see these shrimp in!

My Reef Aquarium
My Reef Aquarium with Forward Facing ‘Shrimp Caves’ On Each Island

It will live peacefully with other tank mates but make sure you don’t have any slow-moving invertebrates, be sure to keep an eye on your snail population as sometimes these shrimp are opportunist predators on them.

This one is also shown to be offensive towards its own species so it is advisable to keep only one or a mated pair in your tank to prevent any fighting.

This shrimp usually grow up to 3 inches in size and with antennae, it will reach up to 6 inches so a minimum 30-gallon tank size is advised. It is an omnivore and can eat a variety of foods and also helps in cleaning the aquarium from dead tissues, fungus, and parasites.

Saron Shrimp

(Saron marmoratus)

Starting Around $5

This one is perfect for beginner to advanced saltwater aquariums alike. It originates from Indonesia, Hawaii, Maldives and is also know as the Monkey shrimp, Buffalo shrimp, and Marble shrimp. It belongs to Hippolytidae family and is mainly a nocturnal creature.

It has a fantastic ability to change colors; green color in the day and red during the night which it uses to help stay hidden in the shadows when in the wild. Tufts of cirri are present in the males distinguishing them from females and either are suited for the aquarium.

It is easy to keep and care for but it will take a slow adjustment to your aquarium before it feels comfortable to begin roaming around during the day, so ensure your tank has lots of dark hiding places because in the start, it will only show up at night.

It can usually be found on the bottom of the tank scavenging and eating leftover dead organic matter but once happy it will also feed on the usual with frozen foods that you feed your fish.

It can grow a maximum of 2 inches in size and can be kept in a +20-gallon tank. 

Bumblebee Shrimp

(Gnathophyllum americanum)

Priced Around $15

This shrimp has a very striking appearance which gives it its name. It can also be called the Stripe Harlequin shrimp and is somewhat similar to Harlequin shrimp. It is present all over the Indo-Pacific region and belongs to Gnathophyllidae family.

It is very small, growing only to around 1 inch that is why it is well suited for nano aquariums! Its body is tan, white, orange, or yellow with black stripes giving it the resemblance to a bumblebee.

A minimum 10-gallon tank will be required for this shrimp and it is never aggressive and always friendly with the tank mates but the risk of getting eaten by the bigger fish is there due to its small size, so peaceful tank mates are a must. This shrimp will need lots of rockwork where it can easily hide when feeling vulnerable or in case of predatory attack from other fish.

To Finish

Keeping shrimp in a saltwater aquarium has great benefits, aside from visually diversifying your aquarium, they will also eat pests and detritus keeping the tank water clean.

Most of these shrimp are omnivores and scavengers so they will eat anything they can find and any supplemental feeding they get will come from the food your feed your fish anyway.

They also do not trouble other tank members and mostly keep to themselves. There are not any reports of shrimps being affected by any kind of parasite or any sickness but they do need oxygenated water for their great health.

As always, prior research is required before choosing a shrimp species for your aquarium to ensure it doesn’t become a meal the second you add them into your aquarium. They can be added soon after your tank has cycled, just be sure to provide them with food if your tank is still sterile and unmatured!

Further Reading

If you found this article useful, I highly recommend these other ones too:

10 Best Peaceful Reef Fish – Perfect for Beginners!

So, you have decided to set up a reef aquarium, which is super exciting and sometimes overwhelming for beginners like yourself.

As there are so many different fish, invertebrates and corals you can add to create the perfect ‘mini-ocean’ in your home, knowing what to put inside can be the trickiest part of starting your new hobby.

As your tank is probably not mature and established yet, you will want fish that are hardy and can live in harmony with one another so you can spend your time perfecting your tank and its maintenance.

Each fish has a different personality making it difficult to select favorites for your tank. Well, to help you decide what fish to put in your aquarium, I have put a list of some of my favorite peaceful fish that would be great for your new reef tank!

My Top 10 Peaceful Reef Fish Perfect for Beginners

Ocellaris Clownfish

(Amphiprion ocellaris)

Starting from $22

My parents always told me growing up “there are no favorites in this house” but I can’t help but love these guys over the others. Popularity since the movie Finding Nemo has allowed them to become #1, not that they needed help before!

It seems it is not only me, but these are also by far the most popular reef fish out there! They are so easy to fall in love with as they swim around the tank in a waddling motion, showing off their bright orange and white striped coloration. You can also find them in white and black colorations and now ‘Designer’ patterns, but they are expensive!

Captive-Bred Oscellaris Clownfish are much hardier than wild-harvested ones, making them great for beginners. They like to be kept in pairs and share the tank with a Bubble-Tip Anemone (Entacmaea quadricolor) to hide and play inside, and to lay their eggs, although they do perfectly well without an anemone – Mine do!

Care Level:Easy
Temperament:Peaceful – Can Be semi-aggressive with eggs laid
Lifespan:3-6 years
Max. Size:3”
Min. Tank Size:20 gallons
Origin:Eastern Indian Ocean & Western Pacific Ocean,
but are now Captive Bred

Green & Blue Reef Chromis

(Chromis viridis)

Starting from $12

The Green Chromis is easy to look after, hardy and has a beautiful shiny green to blue colour making it a preferred reef fish, even for experienced hobbyists. These fish are so peaceful that they can be kept with almost any other reef fish, invertebrates, and even corals – making them compatibility kings/queens.

They love to shoaling and schooling in all areas of the tank, so it is recommended to buy them in odd numbers of 3 or more. They can be known to pick off one another until there is only one left, but using the odd number to a shoal rule seems to prevent that – For whatever reason!

They like to swim at the top of the aquarium and use rocks, corals, and ornaments to hide in when they feel nervous. Because these are very confident open water swimmers they do really well at helping shy fish come out of the shadows.

Care Level:Easy
Lifespan:8-15 years
Max. Size:4”
Min. Tank Size:15 gallons

Royal Gramma Basslet

(Gramma loreto)

Source: Andreas63

Starting from $27

Bursting with color and being relatively small, the Royal Gramma Basslet is a great peaceful beginner fish and is suitable for nano reefs. Due to their origin, these fish prefer caves to hide inside and subdued lighting.

These are peaceful to other fish in the aquarium community but can be aggressive towards their kind for territory, therefore you should only keep one in the community aquarium.

If you want a fish that is active and bursting with color to brighten up your tank, then the Royal Gramma has to be at the top of your list! It took me years before I bought one of these and now it’s one of my favorite fish!

Care Level:Easy
Lifespan:5+ years
Max. Size:3”
Min. Tank Size:20 gallons
Origin:Caribbean & Tropical Western Pacific

Clown/Citron Goby

(Gobiodon citrinus)

Source: Rob

Starting from $30

These adorable fish love corals, especially SPS coral colonies. Their body is yellow with blue stripes around their eyes and gills. They are only small little guys but when they perch in a coral of contrasting color they really pop!

They are peaceful, but they do prefer to be the only clown goby in the tank. You can find them perching on rock and coral just watching the goings on and once you begin to keep SPS coral, especially Acropora’s keen an eye on them as they may like to sit in the same spot on a coral which can distress the coral.

A great little fish, bright in colour that are the ultimate Nano Reef Kings!

Care Level:Easy
Lifespan:5-8 years
Max. Size:2”
Min. Tank Size:10 gallons
Origin:Africa, Fiji, Indonesia & Maldives

Ruby Head Fairy Wrasse

(Cirrhilabrus cf cyanopleura)

Starting from $70

These brightly coloured peaceful fish will fit right into any aquarium!

It has a blue body with a stylish red ‘ombre’ look. This fish is like a mood ring, depending on its mood it will show different shades of blues and purples. When the males want to show off to the females, he will intensify his “Look” – putting a show on for you and your family.

As they are larger reef fish, they will need a larger tank with some shaded areas. They are also keen jumpers, so remember to have a secure lid or a mesh top if you do bring these fish home.

Care Level:Easy
Lifespan:6-8 years
Max. Size:5”
Min. Tank Size:90 gallons

McCosker’s Flasher Wrasse

(Paracheilinus mccoskeri)

Starting from $50

It may not be so easy to pronounce, but this fish is easy to care for and they settle in very well to established aquariums. They get their name from their courting dance when the male flashes his fins to attract the females.

This flasher wrasse is orange with iridescent blue stripes that is super easy on the eyes, making it the superstar in any aquarium.

You will want to place a lid or mesh on your aquarium as these are also eager jumpers and it’s such a terrible waste to lose one that way!

Care Level:Easy
Lifespan:5 years
Max. Size:3”
Min. Tank Size:55 gallons
Origin:Africa, Maldives, Indonesia, Australia

Purple Firefish Goby

(Nemateleotris decora)

Source: Nat Tarbox

Starting from $60

This tubular, colourful fish is very hardy, making it a great fish to brighten up a beginner’s aquarium. They spend their time both near the surface and at the bottom of the aquarium, especially when feeding, also they enjoy taking shelter on live rock, so be sure to add some in for them.

They can be kept in pairs but expect them to soon become parents! These firefish also love to jump out of the tank, so be aware of this when choosing a tank as you will need a lid or mesh. 

They are great fish for helping shy tankmates venture out into the open water of the tank. A great peaceful, beginner fish!

Care Level:Easy
Lifespan:5 years
Max. Size:3”
Min. Tank Size:20 gallons

Pajama Cardinalfish

(Sphaeramia nematoptera)

Starting from $13

These guys have a crazy coloration that will look awesome in your aquarium! They get their name from their red polka dots that look like they are wearing pajamas. They are very peaceful, super-hardy, small, and very affordable too, making them extremely popular, especially for nano reef tank hobbyists and beginners.

All the Cardinalfish like to hover in the tank creating a serene alternate to the movement of very active fish. Paired with Long-Spined Urchins they make a unique pairing as they hang out in the spines of the Urchin for protection.

You can keep them in groups, but when they couple up for breeding, they can become slightly aggressive towards each other.

Care Level:Easy
Lifespan:5-15 years
Max. Size:3½”
Min. Tank Size:20 gallons
Origin:Fiji & Western Indo-Pacific, but now are captive bred

Zebra Barred Dartfish

(Ptereleotris zebra)

Starting from $25

The Zebra Barred Dartfish also goes by the names Zebra Dart Goby, Bar Goby, Barred Dartfish, Zebra Goby, and even Chinese Zebra Goby. Their colouration is incredibly unique, as it cannot be fully captured in photos! The shimmer these beautiful fish create is truely stunning!

These fish are not usually kept by aquarium hobbyists as many people do not know about them But if you can find them in your local fish store or at one of the online suppliers then you will not regret purchasing this fish!

Due to their size and schooling behavior, they should have plenty of room and live rock inside the aquarium to be able to swim, but bolt into safety when they feel threatened. They like to be housed in pairs or small groups, but they need to all be introduced at the same time.

Care Level:Easy
Lifespan:5 years
Max. Size:4”
Min. Tank Size:30 gallons
Origin:Fiji, Indonesia & Maldives

Tailspot Blenny

(Ecsenius stigmatura)

Source: Haplochromis

Starting from $30

These tiny ‘stick’ fish have a defining dark spot at the end of its tail, and a black and yellow line below its eye-it looks like it is wearing eyeliner!

Like other blennies, they enjoy spending most of their time at the bottom part of the tank lying on substrates such as sand and rock, and then darting into small crevices to hide. You should not be placing aggressive fish into the tank with them, as you do not want these little fish to be hiding all the time.

They have strong personalities so they like to show off and often can become aggressive towards their same kind, so it is best you only buy one of these spotty guys for the community.

Care Level:Easy
Lifespan:2-5 years
Max. Size:2½”
Min. Tank Size:10 gallons

To Finish

A beginner fish is peaceful, easy to look after, hardy, and not too expensive (hopefully). Even as a beginner you can still fill your aquarium with a colourful variety of fish from this list. Your family and friends are going to be super jealous when they see your beautiful ‘mini-ocean’ in your home!

Remember that before adding fish to your aquarium, research their needs and compatibility, no one likes bullies in the room – the same applies to your fish in their home!

These peaceful, colorful perfect fish for beginners will ensure your tank is not a constant battle of squabble leading to fish disease and death.

Further Reading:

If you found this article interesting and would like to keep reading, I highly recommend the following articles from my blog:

Best Saltwater Crabs for Beginners – So Fun To Watch!

Crabs can be an enchanting and pleasant addition to your saltwater aquarium. Not only do they look great and add interest, but they also help to keep your reef tank clean! In my aquarium, my platoon of Scarlet Hermit crabs are some of my favorite inhabitants. They are just so unique!

Here are some of the most popular species of crabs for a saltwater aquarium:

  • Mithrax Crabs
  • Anemone Crabs
  • Sally Lightfoot Crabs
  • Halloween Hermit Crabs
  • Pom Pom Crabs
  • Arrowhead Crabs
  • Scarlet Hermit Crabs
  • Coral Crabs

You can choose to buy from a massive crab variety in our hobby so let’s get into a little detail about some of the most popular crabs you will find while perusing your local fish store.

To help you get even more information about the crabs listed in this article you find a geat selection of them at They are a great online supplier and you can find them below:

TBR Recommends Have Some Incredible Deals at Their Constantly Updated Online Store

Mithrax Crabs

Mithrax Crab

The Mithrax crabs (Mithrax sculputus), also known as Emerald crabs have very glossy green bodies and are very easy to care for. They generally like to hide in dark corners during the day and are very much nocturnal, but with a good food supply, you find them munching away during the day too.

These crabs are very popular as they have a habit of eating algae, especially bubble algae. Bubble algae are also known as Valonia and Ventricaria can grow very quickly and can block drains and inlets of pumps ( Trust me I almost found out the hard way!)

To help with the battle of Bubble algae buy the females as they tend to stay more focused and here is a quick video I made on how to easily sexy a crab:

Mithrax crabs are mostly omnivores so they need a lot of green food like dried seaweed if your aquarium is very clean or bare of naturally growing algae. They can be aggressive sometimes and can begin to prey on other tank members when don’t get ample food supply. You will also find them devouring any dead animal it finds.

Most Mithrax crabs thrive in a mature reef tank with ample food sources and plenty of rock to hide. The majority of Mithrax crabs stay small all their life but a few have been seen to grow quite large, especially in a large aquarium. When they get large they can be dangerous to other invertebrates and fish in the tank so it is better to remove them if they start to show signs of aggression

They are capable of growing 2 inches in size and can be bought for around $10.

Anemone Crabs

Porcelain Crab Feeding

Anemone crabs (Neopetrolisthes ohshimai) are known as the cool crustaceans because they are very pretty with brilliant color. Belonging to Porcellanidae family these crabs have a red polka dot pattern on their shells with white edges which give them a look of porcelain, hence why they are sometimes known as a Porcelain Crab.

They have very large claws which they use to hold large meaty pieces that they find, but most of the time they use their fan-likes appendages to catch microscopic food from the water column.

These crabs are very passive and can be kept in pairs. They generally do not show aggressiveness towards other tank dwellers but can raise their large claws to ward off any potential predators when needed.

They are named after anemones that they live within the wild. They can be kept easily without anemones in the home aquarium, but having an anemone will show this symbiotic relationship well.

These crabs can reach as big as 2-3 inches in size and their price ranges from $10 to $20 each.

Sally Lightfoot Crabs 

Source: Tato Grasso

Sally Lightfoot crabs (Percnon gibbesi) belong to Grapsidae family. These crabs have a very striking appearance with a brown body and yellow, red rings on their legs. They are a great tank janitor, cleaning the tank from unwanted organic material.

These crabs are omnivores and scavengers. They feed on detritus, algae, uneaten food, and everything else that comes in their path. If they are given the opportunity they will eat meat, such as other invertebrates and fish. In a new, unmatured tank you can boost their diet with dried seaweed and meaty pieces like Mysis Shrimp, Clams, etc.

They are usually semi-aggressive when small but when getting larger they can get very aggressive and intolerant. These crabs do fine when put in with larger fish but with smaller fish, they can show aggressiveness and harm them or eat them, although they don’t attack corals.

They favor places where they can camouflage themselves easily so they will be in need of a lot of rocks in their aquarium. They also move very quickly which is why they are very hard to catch. These guys are very undemanding.

Their sizes range to 3″ and you can find them for around $20. These can be found in blue, orange, yellow, and brown.

Halloween Hermit Crabs

Source: Haplochromis

The Halloween Hermit Crab (Ciliopagurus strigatus) belongs to Diogenidae family. They are very beautiful to look at and will remind you of the Halloween decorations you had as a kid.

They are a vibrant orange color with red stripes around their legs which makes a nice contrast from the shell. They are very easy to care for as they are omnivores, scavengers, and algae eaters. They will eat detritus, dead organisms, leftovers, cyanobacteria, and algae making them a useful member of your tanks’ clean-up-crew.

If you are keeping them in a young and unmatured aquarium, feed them with shrimp and dried seaweed to help them from starving. They are mostly safe to keep but sometimes they can be aggressive and try to steal food from corals and knock them over in the process once they start to get larger.

As with all hermit crabs they live in shells so make sure you have an extensive supply of different sized shells so they can ‘Move Home’ whenever they feel ready. I just pick up a few shells each time I go to the fish store and drop them in the back of the tank. It is not uncommon for the Hermit Crabs to attack and eat snails to get to their shells if they cannot find a suitable empty one.

For one adult Halloween Hermit Crab, you should have a tank of 15-20 gallons, and be sure you provide plenty of rocks in your tank as these are mainly nocturnal creatures that like to seek refuge within the rocks.

Their sizes range up to 3″ and price range is usually between $12-16.

Pom Pom Crabs

Source: Hectonichus

These crabs are very cute, unique, and mystifying crustaceans. Their color ranges from white to tan with dark markings all over their body which helps them camouflage better.

They belong to the genus Lybia and are called the Pom Pom Crab because it looks like they hold pom poms in their hands, not really, they are used to catch floating food from the water.

The pom poms that they are holding are actually anemones, either from the Triactis or Bunodiepsis species. These anemones protect them against any potential predator and the crabs will wave their anemones to show that they are not the next meal! They also use this anemone for collecting food.

They are very easy to care for and are safe with fish and other pom crabs making them great for additions to a reef tank. They are omnivores and mostly eat zooplankton, but if you are keeping them in a young tank feed them with a variety of food like pellets, brine, and Mysis to help keep them fat and happy.

They are small at around 1 inch in size so can be difficult to see in a large tank, but in a smaller tank, you will have no problem finding them. Another interesting fact about them is that they molt like other arthropods so don’t worry if you see something that appears to be a crab’s dead body lying on the sand bed

Their price ranges from $24 to $39

Arrow Crabs

The Arrow Crab (Stenorhynchus spp.) are commonly called spider crabs, belong to the family Majidae. Their color ranges from cream to yellow with iridescent white and blue stripes and the shape of head and body gives it its name.

These crabs are the most controversial ones because on one hand they look fascinating and on the other, they look like something from an alien or horror movie! They are easy to care for but have territorial and opportunistic predatory nature meaning these are mostly carnivores so it is better to keep them well-fed to prevent them from targeting your livestock.

They are effective in controlling bristle worm infestations but are not the best choice as an addition to a new, unmatured aquarium. They are aggressive towards their own species so it is recommended to have only one crab per tank and having a lot of rock will allow it to hide when it feels threatened.

These crabs are nocturnal and patrol the aquarium at night but once settled you will find them out during the day just doing their thing. They can grow up to 6 inches so it is better that you put them in at least an aquarium of 20 gallons and they do molt like all other crustaceans so don’t get scared that your crab is dead!

Their price ranges from $17 to $40

Scarlet Hermit Crabs

Sometimes known as the Scarlet Reef Hermit Crab, these vivid little critters belong to the family Diogenidae. They are one of the most common crabs as part of an aquarium’s cleanup crew because they are so easy to keep and are far less aggressive compared to the Blue Leg and Blue Knee Hermit crabs.

These crabs are herbivores and are voracious algae eaters, although they are not expected to keep your tank algae free! If you are planning to keep them in your aquarium you should provide them with empty shells and feed them with dried seaweed in a new tank with very little natural food growing in it

They live peacefully with other aquarium members but you have to take caution while adding them to the tank as large fish can prey on these little things. These are perfect for all sizes of aquariums as they are only 1/2″ to 1″ in size and being able to house multiple together makes them a great interesting crab to own!

They are cheap to buy with their price range from $1 to $6!

Coral Crabs

Also commonly known as the Pocillopora Crab, Acropora Crab, or Acro Crab these crabs predominantly live on branches of stony corals Acropora and Pocillopora but will be seen on just about any coral.

There are of a variety of colors with varying color pigments all over their body, ranging from blues, to purples to pinks, making them a very contrasting and pretty crab to watch.

Some coral crabs are very beneficial while some try to eat fellow fish when they get bigger. The good ones that you need to look for are related to Tetralia and Trapezia species. They have a symbiotic relationship with corals as they provide them protection from any potential predators and corals in return provide them with food and shelter.

These crabs can be a little hard to identify because they look different at every stage of their lifecycle so if this is a crab you want to be sure to get pictures of them at varying ages so you can easily identify them in the fish store.

These crabs are carnivores so in an aquarium you should provide them with meaty food particles, although they also eat mucus off of corals. They will need a host for surviving so make sure your aquarium is mature enough and has some established coral for them to inhabit

They only reach up to 1 inch so make great additions to nano tank and larger aquariums and be sure to not mistake them for a hairy Gorilla crab (Xanthid spp.) who will completely eat your corals!

You can buy these crabs for around $30.

To Finish

Crabs are a great and recommended addition to every reef aquarium! Not only do they add great contrast, diversity, and personality to the aquarium, their large appetite makes them an essential part of the tanks’ clean-u-crew.

A selection of different crab species will help to target different food groups allowing your tank to help maintain acceptable levels of detritus and nuisance algae.

Be sure to add crabs slowly as many of the large ‘Reef Cleaner’ packages you see advertised work well when first added, but once their food supply begins to run out, many starve and die.

Further Reading

If you found this article helpful I highly recommend you read these too: