Do Cory Catfish Eat Algae?

Cory catfish are often mistaken for the janitors of a tank as they are bottom feeders. Although they are bottom feeders, scavenging around for leftovers does not make them algae eaters. They may nibble off algae as they search for food, but these tiny fish lean more towards a carnivorous diet. 

Your tank is set up, and you need to fill the bottom level with a small community tank fish that will match your tank’s population. If you are considering cory catfish as an algae eater to keep your tank clean, then you have the wrong fish. So as bottom feeders, what do cory catfish eat?

Do Cory Catfish Eat Algae In The Tank?

These tiny little fish are the vultures of the water, scavenging around for tasty little morsels that will have made their way down to the bottom of the tank.

Although they are scavengers and help keep your tank clean by vacuuming any tasty treats they find in the soft sandy substrate of your aquarium, they are by no means algae eaters.

Cory catfish are not the type of fish you buy to control algae levels in your tank. Although they fall into the omnivorous group of animals and might nibble on algae, they tend to lean more toward a carnivorous diet.

Cory catfish do not eat algae, and careful care must be taken to ensure your cory catfish gets enough food to eat, or you may sentence them to a slow death of starvation.

Top feeding may not be sufficient enough for your cory catfish to have adequate amounts of food to sustain them. You may have to supplement them with a dedicated feed routine of foods that sink to the bottom of the tank, ensuring they have enough to eat.

Matthew Mannell [Public Domain]

Can Cory Catfish Eat Algae Wafer?

Cory catfish can eat algae wafers, although they are not a fan of algae, so feeding algae wafers will not be enough to provide for your little fish.

However, some algae wafers will contain 30% protein, including spirulina, vegetable, fish, kelp, shrimp, and krill, which you will find your cory catfish having a feast on.

When looking for wafers, it’s vital to look at the ingredients on the label. The first few ingredients on the label will indicate if it’s algae-based only or if there is a percentage of protein.

Algae wafers will not harm your cory catfish if they do take a nibble at it. At worst, if they don’t like it, they will just spit it out and move on to finding tastier morsels.

What Foods Do Cory Catfish Eat?

Cory catfish are not picky eaters and will generally eat any leftovers they can rummage from the bottom of your tank.

Don’t make the mistake of thinking that by feeding on the top level, your cory catfish will have enough food from what foods make their way down to the bottom of the tank.

Some fish are incredibly aggressive when it comes to feeding and will devour everything before it gets a chance to reach the lower levels of the tank.

It’s essential to check that your cory catfish get their share of the dinner, and you may need to supplement their diets with a few of their favorite foods.

Remember, cory catfish have huge appetites, so feeding small meals of their favorite foods three to four times a day is ideal.

  • Bottom Feeder Tablets
  • Tropical Sinking Wafers
  • Frozen Bloodworms
  • Live Blackworms
  • Frozen Foods
  • Brine shrimp
  • Frozen Daphnias & Cyclops

Some of their favorite foods include frozen bloodworms.

Pop a small frozen cube of bloodworms in the tank. It will sink to the bottom and thaw out quickly as your cory catfish pounce on the treat and create a feeding frenzy.

Live black worms are also a great option to feed your cory catfish.

You can drop a significant portion in the tank, and the cory catfish will enjoy nibbling on them throughout the day and scavenging for them in the substrate and decorations where the worms will try to hide.

This hide-and-seek game gives them some exercise and recreates their natural environment, where they hunt around for their food.

Frozen vegetable food is also a nice meal for your cory catfish, frozen peas, sliced beans, and even grated zucchini.

Stay away from canned foods; instead, feed them fresh frozen veggies. These will provide your fish with the plant-based nutrition they need in their diet.

Here are a few more vegetables that cory catfish enjoy nibbling on:

  • Squash
  • Cucumber
  • Romaine lettuce
  • Courgette
  • Lettuce
  • Potato
  • Spinach
  • Aquatic plants
  • Bogwood

We previously mentioned that the ideal feeding routine is three to four times a day if possible. Make sure every mealtime offers them a different menu by feeding them something different at each meal.

What Kind of Algae Eaters Can You Keep With Cory Catfish?

If you are looking for fish that will help keep your tank’s algae under control, there are some great species that will love to chow down on some algae while still being compatible with cory catfish and other similar community tank mates.

  • Otocinclus Catfish
  • Bristlenose Plecos
  • Twig Fish

Other fish that go well with cory catfish and other small community tank fish are:

  • Cherry shrimp
  • Mollies
  • Florida Flag fish
  • Rabbit snails

Red Shrimp on Plant

Hints On Reducing Algae In Your Tank

If you don’t have space in the tank for more fish to help reduce your algae count, then there are other ways of controlling algae growth in the tank.

Avoid Direct Sunlight

Algae is a plant, and just like typical plants, it thrives in conditions where it has access to plenty of light, nutrients, and water making your tank the perfect hotspot.

You can help to reduce or slow the growth process by moving your aquarium out of direct sunlight. Even when your tank is out of direct sunlight, you may need to block reflective light or reduce the time your light is turned on.

Add Lots Of Live Plants

Adding lots of live plants to your aquarium may also help slow algae growth. Algae will compete with aquarium plants for the same nutrients and conditions in the tank.

Plants will remove nutrients and absorb carbon dioxide that algae depend on to thrive. But one or two plants are not going to make a difference. To combat algae with plants, you need to create an aquascape.

Clean And Change Tank Water Periodically

Creating a routine water change and cleaning your plants that have any algae can help reduce the green sludge that packs up on your aquarium glass and decorations.

Avoid Overfeeding

Another critical point to help combat algae is to refrain from overfeeding your fish. Don’t starve them, but only give them enough food that they can finish within two to three minutes.


Cory catfish are not picky eaters, and they are used to much worse conditions scavenging for food in shallow, murky rivers of the amazon, so they will eat just about anything. However, algae are not one of those things. Cory catfish are omnivores with the occasional nibble on veggies and plant matters, but their preference is more of a carnivorous diet with protein as their primary consumption.