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How Many Algae Eaters Do You Need In A 55 Gallon Tank?

As the popularity of the 55 gallon tank size continues to increase within the fish keeping hobby, the number of questions that we have noticed people asking about 55 gallon tanks also continues to increase too.

Due to the large tank size, we have noticed a number of people having issues with algae build up in their tank causing people to reach out and ask how many algae eaters they should keep in a 55 gallon tank.

The number of algae eaters that you should keep in a tank of any size is usually a controversial topic when asked on social media as the type of algae eater that you choose to use for your tank will come into play.

For example, an Otocinclus Catfish is going to be able to eat much more algae than a nerite snail changing the actual number of individual animals that you need to keep within your tank.

This is why we wanted to publish our own article going over the topic to try and help our readers get an idea of how many algae eaters you should keep from a wide range of popular algae eaters in your 55 gallon tank.

This should help you balance your bioload for your tank while also helping to make sure that your algae eaters are as efficient as possible at eating as much algae as possible.

How Many Algae Eaters In A 55 Gallon Tank?

The traditional advice is that you should usually keep seven or eight algae eaters within a 55 gallon tank but times have changed and the smaller algae eaters that used to be less common are now popular options.

This means that you may be able to add a large number of nerite snails and get better results in your tank than if you had chosen to add plecos or Otocinclus Catfish to the tank.

In our opinion, the best algae eaters for a 55 gallon tank are the following:-

  • Amano Shrimp
  • Cherry Shrimp
  • Nerite Snails
  • Otocinclus Catfish
  • Siamese Algae Eater
  • Hillstream Loach
  • Plecos
  • Ramshorn Snail
  • Mystery Snails
  • Ghost Shrimp

In many cases, you can mix and match these options to meet your needs but sometimes you should avoid adding some of the options to the same tank but we will go into more detail on this below.

Amano Shrimp

You can usually add around 20 amano shrimp to a 55 gallon aquarium to use them as your algae eater of choice.

Using shrimp to manage the build up of algae, detritus, and left over food is becoming more and more popular within the fish keeping hobby too.

Amano shrimp can work well with some of the other options featured in this article but we would not recommend you keep more than one type of shrimp in your tank at the same time.

As we covered in our article on keeping amano shrimp and cherry shrimp together, the amano shrimp will usually eat any type of neocaridina shrimp you add to their tank due to the amano shrimp being larger and stronger.

In some cases, your main display fish in your tank may eat your amano shrimp too but many people will keep a 2 gallon shrimp tank as a breeding setup to replace any amano shrimp that are eaten in their tank.

If you do want to take this route and use a separate breeding tank to provide a constant supply of amano shrimp to eat the algae in your 55 gallon tank then our article on caring for a pregnant amano shrimp may be worth reading.

Cherry Shrimp

Our regular readers will know that cherry shrimp are our favorite type of shrimp to use as an algae eater in your tank no matter your tank size.

They are cheap, brightly colors, easy to find, and very low maintenance making them the perfect option.

You can usually keep between 50 and 250 cherry shrimp in a 55 gallon tank but in most cases anything over 100 cherry shrimp will be overkill.

Cherry shrimp can go well with some of the other options on this list but as we mentioned above, we would not recommend that you keep them with amano shrimp.

In addition to that, we would also recommend you avoid keeping cherry shrimp and ghost shrimp together too as the ghost shrimp will often eat your cherry shrimp.

You also have to keep in mind that the different types of neocaridina shrimp can cross breed with each other but the young usually revert back to their brown wild type coloring rather than keep the bright colors of their parents.

We go into this in more detail in our article on keeping yellow shrimp and red cherry shrimp with each other but for the most part, you should just choose one type of neocaridina shrimp be it cherry shrimp, blue dreams or neon yellows for your 55 gallon tank to prevent cross breeding.

Nerite Snails

Nerite snails are one of the most common algae eaters within the fish keeping hobby and you can keep around 10 nerite snails in a 55 gallon aquarium tank with minimal issues.

Nerite snails can eat a huge amount of algae relative to their size helping to keep your tank as algae free as possible but this does have a downside.

Because of how much algae a single nerite snail can eat every day, your tank will usually have a rapid build up of nerite snail poop in it.

A cheap gravel vacuum is almost always enough to counter this provided you use the gravel vacuum on your tank at least once per week as a part of your regular tank maintenance.

That said though, in some cases, you may have to spot clean your tank to remove the nerite snail poop two or three times per week.

Another potential downside of choosing nerite snails as your algae eater of choice for your 55 gallon tank is that they can breed at a very rapid pace.

Some local fish stores will offer male or female only tanks of nerite snails to stop this but it is not always accurate.

You may have to add an assassin snail to your tank to help control the nerite snail population as assassin snails eat nerite snails but this should only be done if you are having problems maintaining the population of nerite snails in your tank.

Otocinclus Catfish

The Otocinclus Catfish is our favorite algae eating fish and they can be a great option for a 55 gallon tank due to how much algae they will actually eat

In addition to that the 55 gallon tank size is usually considered one of the better tank sizes for Otocinclus Catfish as they are a social fish that usually like to have five or six Otocinclus Catfish in their tank and by chance, five or six Otocinclus Catfish is the recommended number of Otocinclus Catfish for a 55 gallon tank.

This means that you can add them to your aquarium to start eating as much algae as possible while the fish will also have a high quality of life free from stress.

You do usually need to have some fish hides in your tank for Otocinclus Catfish but for the most part, they are a low maintenance algae eater that can work very well in a 55 gallon tank.

Siamese Algae Eater

The Siamese Algae Eater is another very popular algae eating fish that can work well in a 55 gallon tank but they do tend to eat less algae than the Otocinclus Catfish.

In addition to that, depending on your location, it can be difficult to find Siamese Algae Eaters for sale and some people may missell Chinese Algae Eaters as Siamese Algae Eaters and this can cause a problem.

Chinese Algae Eaters can be an aggressive fish and cause problems in your tank but the aggression levels of Siamese Algae Eater are much lower but if you are not able to tell the difference between the two, we would recommend you go with a different option.

Still, you can keep around five Siamese Algae Eaters in a 55 gallon tank and they will be able to eat most types of algae that build up in your tank with ease.

Ghost Shrimp

Ghost shrimp are the final option in our list of algae eaters for a 55 gallon tank and they can work very well in most situations.

Ghost shrimp are larger than most of the other freshwater shrimp allowing them to eat more algae but just like some of the other featured species in this list, this can cause more poop to be produced.

This means you will usually have to spot clean your ghost shrimp poop with a gravel vacuum on a regular basis.

For a 55 gallon tank, you can usually keep between 20 and 50 ghost shrimp but in some tank setups, a 55 gallon tank will be able to support 200 ghost shrimp but this is not always the best option.

As we said, the more ghost shrimp in your tank, the more poop is produced so you have to keep that in mind and find the sweet spot for your specific setup.


Plecos have seen a huge spike in their popularity in recent years and most types of pleco will eat a decent amount of algae in your tank.

That said, there are a number of different types of pleco that can all grow to different maximum lengths so the number of plecos you can keep in your 55 gallon tank will depend on the specific type of pleco you keep.

if you do want to use plecos as your algae eater of choice we would recommend that you research the specific type of pleco that you want to keep as their requirements can change by a surprising amount.

We have a number of articles going over caring for plecos that may be helpful and worth reading if you do want them as your algae eater for your 55 gallon tank:-

Ramshorn Snail

Ramshorn snails are usually used for ponds rather than aquariums but they can eat a surprising amount of the softer algae types.

Although ramshorn snails can eat a large amount of algae, they will only eat certain types of algae so this can hold them back against some of the other options on our list.

You can usually keep around 25 ramshorn snails in a 55 gallon aquarium though so this can help to offset the lower algae eating yields of the species.

Mystery Snails

Mystery snails are currently the most commonly kept aquatic snail within the hobby due to a number of new color morphs being developed allowing you to move away from the standard ivory mystery snail if you wish.

If you are having problems with hair algae in your aquarium tank then mystery snails can be an excellent option for your algae eater of choice for a 55 gallon tank.

Mystery snails will eat other types of algae but it is usually in much lower amounts if there are alternative food sources available.

For a 55 gallon tank, you should be looking to keep around 10 mystery snails in the tank but they can reproduce at a rapid pace.

This means that you may want to add an assassin snail to the tank to eat the mystery snails if their population does end up getting out of control.

Hillstream Loach

Now, the Hillstream Loach can be a decent option as an algae eater for a 55 gallon tank but there are definitely other options on this list that will eat more algae than a hillstream loach.

We wanted to include the hillstream loach on this list as they are more of a general clean up tank member that excel in other areas that some featured species on this list lack in.

For example, if you want an all round option that will eat algae, biofilm, detritus, leftover food, and pretty much anything else it can find, the hillstream loach is the fish for you.

One of the best things about the hillstream loach is that they will eat lots of live bugs in your tank so if you are having problems with blooms of copepod or amphipod in your tank, this could push the hillstream loach to the top of the list for you.

In most 55 gallon tank setups, you can keep around five hillstream loaches in your tank without having issues but this will depend on the overall stocking levels with other fish due to the additional bioload.