55 Gallon Saltwater Tank Stocking Plan

In this article, I will show you some great ideas for stocking a 55 gallon saltwater tank. 

If you are thinking of setting up a 55-gallon saltwater aquarium, it’s important to plan ahead and have an ideal stocking list prepared.

This is beneficial as you can plan your aquascape and equipment according to the livestock you plan to keep. 

Not only will this save you time but it will be easier to plan your aquascape and save money from buying livestock that might not be suitable for your setup.

Also, aggression can be a concern for all saltwater tanks and planning ahead of time will prevent this problem.

A 55 gallon tank size is a great choice as it is not too large but bigger than a nano tank which gives you plenty of options for stocking.

It is a very commonly used sized aquarium which has the standard dimensions of 

48” L x 12” W x 21” H.

The 4 foot length allows for many different types of fish that you couldn’t keep in smaller sized tanks. 

55 gallon saltwater tank stocking plan

Best saltwater fish for a 55-gallon tank

There are many fish that are suitable for a saltwater tank. You will need to avoid larger fish as they will need additional space than a 55 gallon can provide.

Providing the fish are compatible, many fish that are under 4-5” would be suitable.

A 6 foot tank will be needed for any fish over this size.

Here are some great options:

  • Coral Beauty Angelfish
  • Blue-Green Chromis
  • Clownfish
  • Mandarin Goby

These fish are all compatible with each other and you could keep them together in a 55 gallon tank. 

Coral Beauty Angelfish

The Coral Beauty is a very colorful Dwarf angelfish that will grow to around 3-4” and is a great choice for a 55-gallon tank. They are hardy fish and easy to care for.

They are omnivores and will eat a mix of spirulina, Brine and Mysis shrimp, algae, saltwater fish flakes, and pellets. They are not aggressive unless they are kept in the same tank with another Dwarf angelfish. 

Blue-Green Chromis

Blue-Green Chromis is a small bright colored schooling fish that add a ton of personality to your tank. They are best kept in groups of 5 to 7 although smaller groups are possible.

These fish are very peaceful and won’t bother others in the tank. They are also reef safe and won’t bother corals or invertebrates. They are affordable and readily available at most saltwater fish stores. 


The most popular fish kept in saltwater tanks are clownfish. With so many types available, you won’t run out of options for your tank. 

The Occelarus Clownfish is very common to see in saltwater tanks. They are colorful and have great personalities. They are also easy to care for and not aggressive unless they are defending their territory. Clownfish should only be kept as a single fish or a pair. No more than 2 Clownfish in a 55 gallon tank is recommended. 

Clownfish are hermaphrodites meaning that they are all born as males and can turn into females later in life. But that is not reversible. Once female, they can not return to a male.

If you decide to keep an anemone with your Clownfish, they are also suitable for a 55 gallon tank. 

Mandarin Goby

One of the most interesting fish available for saltwater tanks is the Mandarin Goby. It is very colorful and has unique markings that no other fish has. The Mandarin will grow to around 3” and is a very peaceful fish that is a great choice for a 55 gallon tank. 

The biggest concern with keeping these fish is they need a mature tank to survive and they are recommended for experienced hobbyists only. They are considered difficult to care for as they have very demanding feeding requirements that new tanks can’t provide. 

The Mandarin Goby requires a healthy supply of copepods to feed on. Without them, these fish will starve to death. It is possible to get them to eat other foods but it is very rare and shouldn’t be relied on. If you can meet their requirements for feeding, they are a great option for you.

Read: 9 Best saltwater fish for a 55 gallon tank

Corals for a 55-gallon tank

If your 55 gallon tank is established and ready for corals, there are some that are better than others. If you are stocking your tank with the fish mentioned above, they are all considered to be reef safe. 

When choosing corals for your tank, you need to keep in mind that they can be aggressive and need space to grow. Certain corals will need space in between them and other corals to avoid being stung. In a 55 gallon tank, you will be limited by the width of the tank front to back.

Large corals should be avoided unless there is no risk of them stinging each other. 

Recommended corals include:

  • Acans
  • Zoanthids
  • Frogspawn
  • Mushrooms

These LPS corals are one of the more forgiving and hardy corals to keep. They will do well under low to medium water flow and lighting. 


Acan corals prefer to be placed in the lower to mid sections of the tank. These corals are very colorful and a popular choice for reef tanks. A great choice to add to your 55 gallon tank. 


Zoas are considered to be a beginner coral although many experienced hobbyists will keep them. There are over 100 different varieties of Zoanthids to choose from and the color choices are unlimited. These corals are fast-growing and can easily multiply into new heads quite often. 


This LPS coral is a member of Euphillia coral species. It is a colorful coral that can grow to be large so if you are keeping them in a 55 gallon tank, remember to give them plenty of space.

It is best to start out with frags of Frogspawn coral and either upgrade your tank or frag them as they grow. They have long sweeper tentacles that can sting other corals if placed too close. Other members of Eupyllia corals can be close to the Frogspawn without being stung. Octospawn and Hammer corals are examples. 


Mushrooms are soft corals that are suitable for a 55-gallon tank. They will do well in low to medium lighting and water flow. They are hardy corals and don’t need perfect water conditions to grow.

Many different Mushroom corals are available and they can be placed either on sandbeds or rocks. They are known to split quite often so don’t be surprised if 1 mushroom splits into 2, then into 4, etc. If you are a beginner with keeping corals, mushrooms are a great choice. 

Invertebrates for a 55-gallon tank

  • Cleaner shrimp
  • Emerald crabs
  • Tuxedo Urchin

Cleaner shrimp

One of the most common cleanup crew choices is the Cleaner shrimp. These shrimp are known for being a great cleaner as they can remove parasites and disease from fish in your tank.

They are great for eating foods that don’t get consumed by others. They are very unique and fun to watch. You could have a pair of cleaner shrimp in your 55-gallon tank, providing they will get along with each other.

Emerald crabs

These invertebrates are known for their desire to eat bubble algae and will pick food and algae continuously off your rocks. These crabs are a scavenger and do a great job getting rid of uneaten foods.

These crabs are green in color and are pretty basic looking but are fun to watch. They like to hide in the rocks during the day but can be seen crawling around the tank at night. They are also reef safe and won’t bother your corals. They may pick around the coral but not usually touch the coral itself. You could have several Emerald crabs together in a 55-gallon tank. 

Tuxedo urchin

The Tuxedo Urchin is a very valuable member of any cleanup crew. They are very effective in eating algae and keeping your tank clean. These urchins are nocturnal and tend to hide during the day but can be seen throughout the tank at night. They are very peaceful and won’t bother others in the tank.

The only concern with Tuxedo urchins is they will eat Coraline algae that many people love to have in a mature saltwater tank. They may also need to be cleaned from time to time as things can get stuck in their spines. Rocks, smaller snails, shells. You can have 1 or 2 Tuxedo urchins in a 55-gallon tank without issues. 

How many fish can I put in a 55-gallon saltwater tank?

No more than 5-6 fish small to medium sized fish should be kept in a 55 gallon tank. This could be increased based on bioload and filtration used with smaller fish. 


When stocking a 55 gallon saltwater tank, you have plenty of options. This tank size will allow you to keep certain fish that you couldn’t keep in smaller tanks and you will have more variety to choose from. The fish, corals, and invertebrates mentioned here are an example of a stocking plan that would work well in a 55 gallon tank.