Skip to Content

Siamese Algae Eater vs. Otocinclus (The Key Differences)

Siamese Algae Eater vs. Otocinclus (The Key Differences)
This post is written to the author's best knowledge and is not intended to be used in place of veterinary advice. In addtion, this post may contain affiliate links. As an Amazon Associate I earn from qualifying purchases.

It’s common for people to buy fish to help with cleaning the tank. If you have problems with algae in your community fish tank, you might want to buy fish that are good at eating algae.

There are quite a few options that you can consider. For many, it comes down to buying either otocinclus catfish or Siamese algae eaters (SAEs).

Depending on what you want, one of these fish might be better than the other. However, you might not know much about either if you’ve never purchased algae-eating fish before.

Read on to learn about both SAEs and otos. This will ensure that you can confidently decide which option is the best for you.

They Have Slightly Different Water Parameter Preferences

Water parameter preferences might matter quite a bit when deciding between the two fish. This is because most people want to add algae-eating fish to community fish tanks.

You might be looking for fish that will be compatible with specific fish in the community tank that you already own. Both fish are good community tank options, but they have different preferences that you need to know about.

SAEs do best in water temperatures that range from 75 degrees Fahrenheit to 79 degrees Fahrenheit. It’s best for the pH balance to stay between 6.5 and 8.0.

Otocinclus catfish can do just fine in water temperatures that range from 72 degrees Fahrenheit to 82 degrees Fahrenheit. They can tolerate pH balances from 6.0 to 7.5.

Tank Size Differences

There are tank size differences between the two fish as well. Otocinclus catfish are much smaller than SAEs.

Otos only grow to be between one and two inches long. SAEs will grow to be up to six inches long.

Since SAEs are so much larger, they need to be kept in bigger fish tanks. You’ll have to take this into account when deciding if they’re appropriate for your fish tank.

Otocinclus catfish can be kept in fish tanks as small as 10 gallons. SAEs must be kept in a 25-gallon fish tank or something larger.

Both of these fish need to be kept in small groups to be comfortable in a fish tank. You’re supposed to keep six otos in the same tank, and six of them can fit in a 10-gallon fish tank.

However, it is better to give the otos a bit of a bigger tank so they won’t feel cramped. Even so, it’s good to know that they can fit in a smaller tank if you don’t have room for a large one.

You’re supposed to keep between four and six SAEs together in one fish tank. These fish love to swim together, and they go around the tank eating algae.

Different Feeding Requirements

These two fish have quite different feeding requirements as well. Otocinclus fish are going to mostly eat the algae in the tank.

They can almost survive entirely just by eating algae in the tank. You will need to supplement their diets with other foods because they will run out of algae.

People often feed otos algae wafers when they run out of algae in the tank. It’s also common to slice some blanched veggies for these fish.

They love eating zucchini, cucumbers, carrots, spinach, and so many other veggies. You won’t ever have a hard time feeding these fish, and they will continue to eat algae even if you feed them other things sometimes.

SAEs eat a lot of algae, but they’re omnivores that need to be given meaty foods as well. It’s common for these fish to eat protein-rich foods such as brine shrimp and bloodworms.

You can feed the SAEs live foods, but you can also give them frozen food if you’d prefer to go that route. Either option is fine.

It’s just important to give them a source of protein in their diet. You do need to be careful not to overfeed these fish because they already eat a fair bit of algae.

If you give them too much food, they might stop eating algae. That wouldn’t be good because most people buy these fish specifically to keep algae under control.

Which Fish Is Better at Eating Algae?

Most people agree that SAEs are by far the better algae-eating fish. If your goal is just to pick the fish that will eat lots of algae, it’s better to choose SAEs.

This is because SAEs eat a lot of algae, and they can help to control troublesome types of algae, such as black beard algae. So for many, SAEs will be the ideal choice.

That doesn’t mean that otos are a bad choice, though. Otos can be great algae-eating fish, and many like them specifically because they’re so small.

Otos are some of the best fish when it comes to controlling brown algae. So picking these fish for your tank will also have merit.

It’s also worth noting that otos never get bored with eating algae. SAEs might focus more on eating other foods when you offer them to them, and that might mean that the algae will get ignored a bit.

Your final decision about which fish is best might come down to what type of algae you’re dealing with, the size of your tank, and what tank mates you want to put the fish with. You have to consider many factors other than what types of algae the fish will eat.

Otocinclus Catfish Are Much More Sensitive

One thing to keep in mind when deciding between these two fish is that otos are much more sensitive than SAEs. Sadly, otos are very vulnerable to problems with ammonia poisoning.

If the water doesn’t stay pretty clean, these fish are going to be in danger. It makes it harder to keep otos alive, but that doesn’t mean that it’s impossible.

You just have to stay on top of tank maintenance when caring for these fish. This isn’t always the most convenient thing in a tank where you’re trying to grow algae, though.

When taking care of otos, you must change the water weekly to be safe. Otherwise, the ammonia and nitrite levels will spike, and you’ll be dealing with sick otos.

It’s also notable that otos have a tough time acclimating to new tanks. Sometimes otos just die because they’re stressed when moved to a new tank.

This isn’t something that you have to worry about with SAEs. They’re a lot sturdier, and many would consider them to be better for beginners or those who don’t have a lot of patience for slightly more fragile or sensitive fish.

Can Otocinclus Catfish and Siamese Algae Eaters Live Together?

You might be surprised to hear that you can keep Siamese algae eaters and otocinclus catfish in the same tank. The water parameters do overlap a little bit.

The SAEs won’t bother the otos if you keep them in the same tank. Keeping these fish together may not be the most practical choice, though.

You need to ensure that there’s enough algae for both types of fish. Since both fish eat quite a bit of algae, it might not be a good idea to put them together.

Some people have found success keeping both in the same tank, though. So it just depends on your situation.

Good Tank Mates for Siamese Algae Eaters

There are many great fish that can be kept in community tanks with SAEs. These fish are commonly kept in community tanks with various types of barbs.

You can also put danios fish in the tank with these algae-eating fish. Tetras can work well, and so can guppies.

Gouramis can work, but you must choose docile gouramis. Otherwise, you might run into problems.

Good Tank Mates for Otocinclus Catfish

Otocinclus are smaller and peaceful bottom-feeding fish. They can get along with many other peaceful fish that are around the same size.

Mollies will be excellent additions to community tanks with otos. Rasboras are another type of peaceful fish that you might wish to consider buying.

Both cory catfish and clown plecos are known to work fine in tanks with otos. If you want to try something different, mystery snails can be kept in the same tank as these fish.

Final Thoughts

You’ve learned a lot about both otocinclus catfish and Siamese algae eaters. Both fish are appealing, and you might even want to get both of them.

It’s technically possible to keep otos and SAEs in the same fish tank. However, it’s not a practical choice for many tanks since you might run out of algae too fast.

Otos are smaller fish and might be better for certain types of aquariums that contain small and peaceful fish. SAEs are also peace-loving fish, but they’re a bit bigger and can be in an aquarium with some slightly larger types of fish.

Both of these fish are great at eating algae. SAEs can eat black beard algae, while otos are better at focusing on brown algae.

Choose which of these fish you want to put in your community fish tank. You can’t go wrong with either option, but you might want to base your decision on what type of community fish tank you’re trying to put together.