Nobody likes the sight of algae in their aquariums, but they are a natural thing in any water ecosystem so we’ll all have to deal with more or less of it eventually.
There are many methods to keep algae growth under control, including performing regular maintenance on the tank or using various chemical treatments.
However, the best method is the natural one: adding algae eaters in your tank. This way, you will have happy livestock AND a better looking aquarium. It’s a win-win situation!
But as you probably imagine, most of the fish in the aquarium don’t really favor eating algae. So… what are the best algae eaters for your fish tank? We’ll talk about them all today.
The best algae eaters in freshwater aquariums are Siamese Algae Eaters, Bristlenose plecos, Nerite Snails, shrimps and the Otocinclus Catfish. A combination of two different algae eater species will usually deliver better results.
Now let’s get a bit more in depth and see what can we expect from each of the recommended ones above (and look at a few other options).
1. Siamese Algae Eaters
I think that their common name is a clear indicator of the fact that they indeed like to feast on algae.
Also known as SAE, they are generally considered a top choice when it comes to fish that eat algae in freshwater aquariums.
And that is mostly true.
SAEs will be very active when they are younger and smaller, but as they grow older they will get really lazy and stop consuming that much algae.
They also grow pretty large (around 6 inches as adults) so they need larger tanks – minimum 25 gallons.
But overall – and especially early in their life – they are a great fish that keeps the tank algae free. They are docile and peaceful, so perfect for community tanks – and they also look really good!
2. Bristlenose Plecos
Most catfish are good algae eaters, but the Bristlenose Plecos are the best of the bunch.
You always see them in aquariums glued to the glass with their wide mouths open. Well… that is a lot of room for suction and they use it all to feast on the algae in your aquarium.
Even though I don’t consider them among the best looking fish you can have in your tank, I have to admit that they are very useful for keeping it clean.
Unlike the SAE, they never get tired of eating algae no matter how old they are. The are also smaller and extremely hardy, but also friendly fish. So a great choice for most aquarists.
Related reading: Best substrate for planted tanks.
3. Nerite Snails
Most snails will eat algae, but the Nerites have a big advantage: they won’t reproduce in your tank, so their population won’t get out of control as it usually happens with other snails.
They do have a disadvantage: they are really slow, so get 5-6 of them for a 5 gallon tank and over 10 for larger tanks.
These snails look amazing (they are also called Zebra snails because of their colors and lines) and they will eat algae mainly from your aquarium glass. They won’t attack plants and won’t multiply, which is always an added bonus.
However, they are pretentious in regards to the water quality, so make sure that the parameters don’t get out of control.
4. Shrimps (Red Cherry Shrimp, Amano Shrimp etc)
I absolutely love shrimp – of all sizes and colors. Any shrimp will clean up your tank and even though they won’t deal with some types of algae (like the BBA or black bearded algae that nobody eats), they do a good job at keeping your tank algae-free.
Green algae – which is really common in aquariums – is something that they really like to feast on.
Unlike pest snails, even though they multiply like crazy, their bio-load is close to zero, so even though you’ll probably end up with hundreds in a larger tank, they won’t negatively impact the quality of the water.
All in all, shrimp are a great choice – especially Red Cherry Shrimp which are hardy and can do well in all sorts of waters, be them warmer or colder, better or lower quality.
5. Otocinclus Catfish
This is my personal favorite, mainly because it’s one of the smallest fish that enjoy eating algae – and it does a good job at it even when they get older.
Ottos (as they are commonly called) will only grow to around 2 inches, are extremely peaceful and hardy fish and they look a lot like SAEs.
It’s very nice to look at them as they clean the larger leaves of your plants (just like young Siamese Algae Eaters do), but also act as bottom feeders and glass cleaners. A really good choice overall!
6. Guppies & Mollies
All live bearing fish will eat algae to some extent. They are not really focusing on that, but they do help in keeping it under control.
Guppies and mollies will usually consume hair algae mostly, but won’t stay away from some other types of algae.
They are probably the least effective when it comes to keeping algae overgrowth under control, but they are some of the easiest fish to care for, and you can keep a male-only population if you don’t have enough room for their ever-growing numbers.
7. Twig Catfish
As I said, all catfish are considered good algae eaters, but I have to highlight the Twig Catfish as one of the best options.
It has a really nice shape and looks really good in aquariums (when you see it, that is – because it also is a really shy fish!). It does a good job at eating algae and keeping your aquarium clean.
It grows to around 4 inches – so it’s not a good choice for smaller tanks, but at least it’s very friendly and suitable for community tanks. It’s actually very shy and will spend most of its time hidden.
8. Pest Snails
If you want to get rid of your algae problem, but replace it with a snail problem, you have this as an option.
All pest snails – like the Ramshorn snail, the Malaysian Trumpet snail and so on will eat all algae in your aquarium (as well as some plants).
They are great for algae control, but many aquarists don’t like them because they end up in huge numbers and look like bits of mud on the aquarium glass.
I personally enjoy them and have no problem with their growing numbers – although some population control is always welcome – but it all depends on your personal preferences.
If you don’t want them taking over the tank, you have a lot of other good options above anyway.
Best combos for clean aquariums
As I said, I recommend going for a combo of 2-3 of the species recommended above for the best results.
While have one single type will still do well (especially if you have higher numbers), I actually prefer to mix and match: not only for diversity, but to increase the chances of all type of algae to be destroyed.
I personally use a mix of shrimp, nerite snails (as well as Ramshorns) and Ottos and they do a great job. Any mix of fish/shrimp, fish/snail or even just using shrimp and snails would be good, though.
Do you have other favorites when it comes to algae-eating fish or other animals? Let us all know by sharing your thoughts below.