The 29 Best Saltwater Algae Eaters for Your Aquarium

You are finally home with your new saltwater fish and have them all set up in their new home, an aquarium. They seem content and happy, but you start noticing something growing on the inside of the aquarium. It seems to be algae! But how do you go about removing it? You get an algae eater!

The best saltwater algae eaters for your aquarium come from the following types of fish and inverts:

  1. Crabs
  2. Snails
  3. Blennies
  4. Tangs and Surgeonfish

To learn about the varieties of these water dwelling creatures that can help with your saltwater algae problem, continue to read. I have all the details you’ll need on the algae eating critters you can add to your saltwater aquarium to help maintain a clean and health tank. If algae eaters aren’t going to work for you, you will also find extensive information on other options for algae removal.

Algae Eating Critters

Creatures that eat algae as their main source of nutrition are an excellent resource for your aquarium. They will help keep it clean while also keeping your main pet company. And they look great in the tank too!

Seriously, it is the easiest and coolest way to help maintain your tank and keep your fish healthy.


Hermit crabs that are reef safe are great for saltwater aquariums. They eat all different kinds of algae and detritus as their main diet. These creatures crawl over the rocks and substrate that are in your tank eating as they go. They have the added benefit of being small, so they will not get in the way or knock over any of your décor.

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Halloween hermit crab: The Halloween hermit crab will eat red slime algae. It has bodies and legs that appear to be bright orange, with red banding surrounding them. It can grow up to one- and one-half inches.

Dwarf blue leg hermit crab: The dwarf blue leg hermit crab grows to about an inch in size and will eat red slime algae.

Dwarf red tip hermit crab: The dwarf red tip hermit crab eats red slime algae and will sift through the sand as well.

Dwarf Yellow Tip hermit crab: The dwarf yellow tip hermit crab is also small like the dwarf blue leg hermit crab, as they only grow up to one inch as well. They can get into all of the places throughout the tank with no issues.

Dwarf zebra hermit crab: The dwarf zebra hermit crab has a very large left claw that is used to stave off its enemies by holding his claw-like a shield in front of its shell. They tend to hide during the day and look for food at nighttime.

Electric orange hermit crab: The electric orange hermit crab has bright orange legs and blue eyes. It can grow up to two inches, and it will eat detritus and other uneaten food.

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Electric blue hermit crab: The electric blue hermit crab, on the other hand, has bright blue legs, an antenna of bright orange, and black banding on its legs. His claws are brownish green and are pretty much the same size. He also eats red slime algae.

Scarlet reef hermit crab: The scarlet reef hermit crab is a crab with red legs, yellow faces, and can end up being up to one- and one-half inches small.


Snails can be great at eating the algae in your tank, as they are herbivores and they do not turn around because they will fall over. They tend to spend most of their time hanging from the rocks or on the tank’s glass. They are great at cleaning the algae off of these things.

Margarita snail: The margarita snail eats a lot of algae, and if their food supply runs out, they will die as well. They can get themselves back up if they fall on their shells. You should only have a couple of these in your aquarium, as too many may cause their food supply to run out, which will end up killing them all.

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Chestnut cowries: The chestnut cowries require diatom and microalgae to survive. They will die from, starvation if they do not have any algae to eat.

Banded troches snail: Banded troches snails can grow up to three inches, and they eat cyanobacteria and diatoms but not the macroalgae. They can get back up if they get knocked over, unlike most snails. They can easily clean your aquarium walls, the rocks, and the substrate.

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Nerite snail: Nerite snails are snails that are sensitive to copper and nitrates in water, and they also come in many varieties of shell markings and size.

Zebra turbo snail: The zebra turbo snail only grows up to two inches, and they need microalgae and diatom to live.

Mexican turbo snail: Mexican turbo snails are the largest snails on this list, growing up to six inches. They need diatoms and microalgae to live as it is their only diet. They also may eat some hair algae as well if they are on the rocks or a tank’s glass.


Blennies would make an adorable addition to your community tank. In addition to eating the algae off of your tank glass, rocks and other surfaces, their narrow bodies and big eyes give them a lot of character. They are also herbivores, so they generally spend most of their time eating algae of all kinds.

Shortbodied blennies: Shortbodied blennies tend to graze on some algae, but they prefer eating polyp stony coral. However, they are not recommended for hobby aquariums.

Sailfin blenny: The sailfin blenny has the nickname of lawnmower blenny, because of how it devours green hair algae and it does it quickly. It spends its days plowing through algae and eating it.

Seaweed blennies: Seaweed blennies tend to eat microalgae and can help keep its population down. It is aggressive against its species but will not bother any of the other creatures sharing the tank with it.

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Marbled blennies: Marbled blennies likes to relax on rocks at nighttime, grazing on the algae found there. You might not see them active during the day, but they’re still doing their job.

Horned blenny: The horned blenny can grow up to two and a quarter inches. It is an herbivore and enjoys eating algae. It will get along with your other fish and creatures in the tank very well.

Tangs and Surgeonfish

Surgeonfish and tangs are great at cleaning the rocks and the tank glass. They are herbivores that only will eat algae, and they do not consume anything else, keeping your corals safe. Though some of the tangs may get too big for smaller tanks.

Blonde naso tangs: Blonde naso tangs are usually very peaceful surgeonfish. They are herbivores that prefer to eat brown macroalgae. However, in the wild, they tend to eat dictyota and sargassum instead. Some of these fish refuse to eat the algae because of this; however, some do adjust their fate when it comes to eating algae.

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Pacific blue tang: Dory from Finding Nemo the movie was based on the pacific blue tangs, which are a little different than other tangs. They can eat algae, but they also need meat in their diet as well. This is unusual for tangs, but like other tangs they still need the algae in their diet.

Red Sea sailfin tang: The red Sea sailfin tang eats leafy microalgae, along with anything that is considered greens. If there is a tank that has a lot of algae, it is the perfect place for these fish.

Chevron tang: Chevron tang fish are great at eating algae; they enjoy microalgae but will also eat green hair and brown diatom algae as well. Because of its bristle-like teeth that they use to eat detritus, it is known as the bristletooth tang as well. Detritus contains minute algae instead of the filamentous algae that other tangs tend to eat. These fish prefer marine algae along with frozen formulas that have spirulina or algae.

Goldrim tangs: Goldrim tangs are shy fish, but they do become more active once they have adapted. They eat all sorts of algae and need a very large tank to hide in.

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Kole tang: Kole tang fish likes to spend its time eating all different kinds of algae. These fish hail from beautiful Hawaii and are considered delicious. They were also considered to be “royal” food, so if a commoner ate one, they would be killed right away. These fish spend a lot of time during the day eating and grazing, so if you have a tank with a lot of algae, this is the best fish to put in it.

If you put a kole tang fish into a small reef tank, they will damage any algae or plants you want to keep in there. So only get these if they are in a larger tank with a lot of algae that can grow back easily. They also eat flake foods that are made from dried marine algae as part of their diet.

Purple tang: The purple tang is found in the Arabian Sea along with the Gulf of Aden and waters that are off of Sri Lanka. They can grow up to ten inches, so they need a large tank to live in so they can move around while eating algae.

Convict tang: The convict tang fish are fish that are found where fine filamentous algae live. This area does not have a lot of coral, but it does have stones and rocks where algae grow in abundance.

Powder brown tang: Powder brown tangs tend to be a popular fish but are also high maintenance. They do not like the presence of their kind and need places to hide when scared. They tend to eat filamentous micro and some other smaller fleshy microalgae. They need to be fed three times a day at least, and they need marine algae along with Spirulina, or blue-green algae. They are herbivores that prefer macroalgae and require a large supply of it.

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Clown surgeonfish: The clown surgeonfish prefers marine algae and lives in the oxygen-enriched shallow water of a reef. It prefers to stay away from its kind, and it needs a lot of room to move but also prefers to hide behind cover as well.

Orange shoulder tang: Orange shoulder tang fish are omnivores that eat filamentous algae, detritus off of sand bottom substrates, and diatoms. It needs to be kept in an aquarium that has an open sand bottom and a lot of algae to eat. It can also eat marine algae and various meats or shrimp.

Yellow tang: Yellow tangs are very popular fish that are kept in saltwater aquariums. They enjoy grazing on algae in larger tanks, but they can damage any coral that is in your tank. These fish are herbivores, and they need a consistent diet of algae. They tend to graze a lot and prefer vegetables to meat.

All of these reef-safe algae eaters will not destroy your tanks or harass the other inhabitants in your aquarium. They will make a great new addition to your tank and are more aesthetically pleasing compared to protein skimmers. They are the most recommended of all the treatment options for algae. The more popular ones tend to be tangs, surgeonfish, and angelfish.

How Does the Tank Get Algae?

Are you getting red slime, green hair, bubble, brown diatom, cyanobacteria, or other types of algae in your tank? If you have an algae problem, there may be a few possible reasons behind this.

  • Intensity or the quality of the light in the tank.
  • How many nutrients do the algae have to feed on?
  • How much phosphate and nitrate or silicates can they consume?
  • Using the wrong source of water (tap water contains these things, so do not use it).
  • You are not cleaning the aquarium often enough or properly.
  • There is not enough water in the tank.
  • Nothing to keep the algae away.

Macroalgae is okay in a tank, but it is when there is an overgrowth of the algae that it becomes a problem. You need to take proper care of your aquarium to reduce the growth of algae inside of it. Algae in your tank is a natural thing, it is okay to have some, but having an excess of it is not a good thing.

How to Remove Algae

If you go with a saltwater algae eater, you may not need to remove the algae by hand. However, there are alternatives if your algae eater cannot keep up with eating the algae. These include the following:

By Hand

You can remove any extra algae by hand if you prefer, but it may be harder than using a critter to do it. You can also use a filtration system or a siphoning system.


Does your lighting need to be adjusted? This might be why the algae are growing; the light’s intensity may be too high or low. If you have brown algae, you need to increase the amount of light in your tank wherehas if you have green algae, you will want to decrease the light.

Water Flow

Decrease or increase the water flow and circulation that is in your aquarium. If you have a lot of algae, keep in mind certain types prefer certain currents. For example; the cyanobacteria types, such as red slime algae, enjoy the low currents whereas the hair or filamentous species tend to prefer the higher currents.

Grow Macroalgae to Compete

Macroalgae can be used to compete against other kinds of algae. Macroalgae is considered the “good” algae that you may want in your tank. They can limit the growth of the unwanted algae, such as hair and red slime algae, along with bacteria and fungus. Since all of the algae will compete for light, space, and nutrients available to them, the macroalgae will limit the growth of other types of algae.

Chemical Products

You can use chemicals to remove algae, but it isn’t ideal. The best way to deal with algae is really to maintain your aquarium better. Doing so will reduce the number of algae growing inside the tank.

If you take good care of your tank, you should not see too many algae in it. If you decide to buy some over the counter chemical products, keep in mind, they will produce nitrite and ammonia in the water and increase their levels. Keep an eye on the quality of the water in your aquarium if you go this route.

You can treat it with copper sulfate, as long as you only have a fish tank and no other creatures in your aquarium like corals, or rocks. You will not have an algae problem if you do this.

Removal of Nutrients

You need to remove any extra nutrients in the tank through protein skimming. Protein skimmers help keep your aquarium clean. They are helpful in the removal of algae and preventing its overgrowth.

What is a protein skimmer, you ask? Well, it is a device you put in the water that “skims” out the bad stuff and keeps the good stuff. For example, the skimmers work by producing microscopic bubbles that contain the excess nutrients, and when they go into the collection cup, they burst, and you can see everything that they cleaned out.

How Does a Protein Skimmer Work?
The “bubbles” attract the gunk and then float to the top where they deposit the gunk they collected. Essentially, the gunk molecules will stick to the bubbles and get dragged up to the top of the tank where the gunk is deposited. The gunk gets put into a cup when the bubbles burst to prevent the gunk from falling back down into the water.

The size of the protein skimmer’s bubbles does matter. This is because, in order for the skimmer to do its job correctly, the bubbles need to be the correct size to work. Then when the perfect bubble is created, it helps clean out the nutrients in the tank.

Limewood used to be used for this purpose in the past; however, nowadays, there are various ways to skim the gunk molecules out by this process of protein skimming.

Co-Current Skimming

Basic co-current skimming is when you use an open-ended cylinder or tube and mount the bubble source at the bottom. This skimmer uses the volume of the oxygen bubbles that rise in the column to have them meet up with the water in the chamber. The water then comes up from the bottom, and the bubbles hit the collection cup at the top of the tank, then they burst released the gunk into the cup and the purified water back into the tank.

This method does work but is not considered very effective. There are other skimming methods that work better than co-current skimming does, so consider them first before trying this method.

It is a method that has been around for a long time, but as other more effective ways have been developed, most aquarium owners have stopped using the co-current skimming compared to how much it was used before. This is because of the length of time the water and bubbles are in contact. The tubes are not large enough to handle a lot of water to be processed, so the process takes longer.

Counter-Current Skimming

Counter-current skimming is when they double the “dwell time,” or the length of time the water and bubbles are in contact in the tube. The water gets injected at the top of the tube where the reaction happens, and then the bubble source is placed at the bottom of the reaction tube.

When this happens, the water has to through the bubblers, or “counter” them as they rise. This doubles the “dwell time” in the reaction tube and allows the skimmer to be more productive. This is one of the designs that companies use today.

Venturi-Style Skimming

The Mazzei Injector Company came up with the Mazzei valve. Skimmers that use this method are known as venturi-style skimmers. They use the venturi valve to deliver both the bubbles and the water that needs to be treated at the same time.

The water enters at high velocity from the left of the valve is bottle-necked at its molded wasp waist. It has an intake nipple that is at the top of the tube, and the water movement creates an air-draw, which is where the bubbles are formed inside of the tube. The froth that is produced ends up exiting the valve and gets introduced into the main skimmer’s body where the gunk gets removed.

Because of the venturi-style skimmer, the “Dwell time” is multiplied by a high factor since it creates a vortex. Many professionals used to use this skimmer type, but now only a few use this method of skimming.

The venturi-style skimmers require an outlet pipe at the bottom for the volume of water that they process in an hour. This necessitates a “flow-through” type of design. The effluent is usually higher on the skimmer’s main body and is directed back into the display tank.

If you prefer, you can modify a powerhead to provide the same results as a venturi-style skimmer. This allows small volume powerheads to be available for smaller skimmers. There are also some hang-on style skimmers that use the modified powerhead for their main pump.

They copy the venturi-style skimmer’s design by allowing the air to be drawn into a housing with an impeller. This impeller chops at the water and air mixture and sends it into the skimmer.

ETS and Down Draft Skimming

The ETS skimmer is a simple design that became popular in the mid-2000s. This was initially introduced to the hobbyist and is also known by the name down-draft skimmer. These can process very large volumes of water, and many big tank owners use these.

These models are a long tube connected to a display tank, which then gets a bio-ball placed inside of it. This bio-ball is used to diffuse the high-velocity water that goes through the top of the container. These end up getting the water smashed between the bio-ball for multiple times.

Once the water reaches the base of the container, the water is foamy and white. The baffle in the display tank ends up creating the “dwell time.” It also enables the froth to rise into the tube that has a collection cup placed above it. This froth is rich in proteins and gets left in the cup.

Hang In/Hang On Tank Protein Skimmers

These are counter current protein skimmers, and they are simple devices that were the first type of skimmer to be used in the saltwater aquarium hobby. These devices pump the air driven stone, and the bubbles get the collected proteins and put them into the collection cup.

These are the least expensive skimmers that are also easier to install and use. You do not have to worry about wet floors while using this type of skimmer.