10 Best Algae Eaters for Freshwater Aquariums

Algae is a common problem in freshwater aquariums but it’s an issue that is frequently misunderstood. Excessive algae growth isn’t always caused by poor tank maintenance, so it’s important to determine what’s causing the algae to grow out of control before you take steps to mitigate it.

If you’re not dealing with a full algae bloom and just want to keep minor algae levels under control, consider adding an algae eater to your tank. There are a variety of different options to choose from including snails, shrimp, and fish. We’ve assembled a list of the ten best algae eaters below.

1. Mystery Snails

Available in a wide range of impressive colors, mystery snails make gentle additions to the freshwater cleanup crew. Though they start off quite small, these snails can grow to 2 inches in diameter within a year. Some species get even bigger.

Mystery snails will eat a variety of algae types and they’re mobile enough to reach just about any surface in the tank. They are highly adaptable, accepting a wide temperature range, though they do prefer slightly alkaline water. You’ll also need to make sure there’s enough calcium in the water to keep their shells healthy.

2. Nerite Snails

If mystery snails are a little too large, nerite snails might be a better option. They only grow to about an inch in diameter, but they can be just as attractive (and effective) as mystery snails. Nerite snails are easy to care for and their smaller size makes them a more appropriate option for nano tanks.

One thing to keep in mind with nerite snails is that they tend to lay eggs. The eggs are small, flat, and white but they generally won’t be fertile. You shouldn’t have to worry about your nerite snail population getting out of control, but some aquarium hobbyists don’t like the look of the eggs all over their driftwood.

3. Ghost Shrimp

A species of freshwater dwarf shrimp, ghost shrimp (Palaemonetes paludosus) make excellent additions to a cleanup crew. They’re named for their clear bodies, though many exhibit light brown or green spots. These shrimp grow up to 2 inches in length, so they’re a good choice for small tanks.

While ghost shrimp will eat some algae, they’re omnivorous which means they’ll need other types of food as well. Shrimp are also very sensitive to changes in water quality, so it’s important to keep the tank very clean.

4. Neocaridina Shrimp Species

Another group of freshwater dwarf shrimp, Neocaridina species include favorites like cherry shrimp and green jade shrimp. This group of shrimp is a little hardier than some – like Caridina species – but they still need high water quality. What makes many of these shrimp stand out is their vibrant coloration. They tend to do best in large groups with their own kind in tanks with peaceful fish.

5. Caridina Shrimp Species

The most popular species in this group is the Amano shrimp (Caridina multidentata). Amano shrimp grow up to 2 inches in length and have semi-transparent bodies covered in dark spots. Like other dwarf shrimp, Caridina species do best in large groups with their own kind. They’ll need some supplemental food, but their biomass is very low, so it’s easy to keep large groups in a relatively small tank.

6. Florida Flagfish

While many of the fish commonly included in freshwater cleanup crews are of the “sucker” variety, the American flagfish (Jordanella floridae) is not. These fish are brightly colored and they’re one of the best algae eaters for controlling stubborn algae types like hair algae and black beard algae. Florida flagfish are named for their striped patterning which resembles the United States flag.

The thing to keep in mind with this algae eater is that it has a voracious appetite. These fish have a habit of damaging delicate plant leaves as they feed and their high activity may distress calmer fish.

7. Hillstream Loach

If you’re looking for something unique to add to your freshwater cleanup crew, the hillstream loach is an option to consider. These fish look like miniature stingrays, and they display impressive patterning. The hillstream loach remains fairly small, growing up to 3 inches in size, and they’re covered in light-colored spots and dark stripes.

Hillstream loaches are the most effective for controlling diatoms and other algae that grows on flat surfaces. They are generally peaceful fish but can become territorial against their own kind, so it’s best to keep either one alone or a group of three to avoid bullying.

8. Chinese Algae Eater

While most of the algae eaters on this list are peaceful species, the Chinese algae eater has a reputation for being aggressive – especially as they age. This makes them a poor choice for many applications, but they are algae eaters that can hold their own with semi-aggressive fish. Just know that they grow up to 10 inches long, so you’ll need a large tank.

9. Red Lizard Whiptail Catfish

Like the hillstream loach, the red lizard whiptail catfish – or simply the red whiptail catfish (Rineloricaria sp.) – has a very unique appearance. These catfish are all-red in color and their bodies are very thin and twig-like. This species tends to be nocturnal, and they only grow to about 4 ½ inches in length. The thing to keep in mind with this species is that they’re more effective in eating leftover fish food but may become less effective as algae eaters as they age.

10. Bristlenose Pleco

Plecostomus are some of the most well-known algae eaters. Unfortunately, they’re also known for getting very large and they tend to become aggressive as they grow. Bristlenose plecos (genus Ancistrus) are a more peaceful alternative and they only grow 4 to 5 inches. They’re great for keeping driftwood clean and will make quick work of uneaten fish food.

When adding these best algae eaters to your aquarium, don’t make the mistake of assuming algae growth will provide sufficient sustenance. Depending on the type of algae eater you choose, the size of your tank, and the other inhabitants you stock, you may need to offer food several times a week – even daily.

Choose a product appropriate for the type of algae eater you’re stocking. Sinking pellets or wafers work well for most bottom-feeders. You can also try treat tabs which you press into the side of the aquarium – these work well for mid-dwelling species.