Feeding corydoras and other bottom dwellers

Short answer: bottom dwellers like corydoras, loaches and many catfish need food that sinks and stays down long enough for them to find it. Flakes that faster mid-water fish grab first will slowly starve them. Feed a sinking wafer or pellet once the tank has settled or after lights-out, offer some variety, and give enough that a little reaches the floor without fouling the water. That, plus a clean substrate, keeps a group of corys fat and active for years.

Why bottom feeders get missed at dinner

Most community food floats or drifts, and your quickest fish clear it from the surface and mid-water before it ever reaches the bottom. Corydoras and other bottom dwellers forage along the substrate, so by the time they get there the meal can be gone. They rarely starve overnight — it happens slowly, as a fish that looks fine gradually goes thin over weeks.

The fix is food designed to sink and hold together on the bottom, fed in a way that gives the floor-feeders their turn.

Sinking foods that actually work

Aim for a small staple plus some variety:

• Sinking wafers — a soft disc that drops straight down and softens where the fish can work at it. Our Hikari Sinking Wafers are a reliable staple for corydoras and loaches.
• Veggie rounds — a plant-based sinking round suits the grazers and rounds out the diet. See Omega One Veggie Rounds.
• Algae wafers — useful for plecos and other grazers sharing the bottom; the mini algae wafers are sized so smaller fish can finish one before it fouls.

Rotate in the occasional frozen or freeze-dried treat such as bloodworm to keep the diet varied. You can see the wider range in our fish food collection.

Corydoras are not a clean-up crew

This is the myth that costs the most fish. Corys, loaches and catfish are not there to eat everyone else's leftovers or clean the tank — they are foraging fish that need their own proper meals every day. Waiting for scraps is not a diet. If you keep bottom dwellers, feed them directly and deliberately.

Browse the bottom-dwelling fish themselves in our cory collection and the wider catfish collection.

How much, and when

Feed a small amount and watch. A wafer or a few pellets that are found and finished within a few minutes to an hour is about right; food still sitting there hours later means you gave too much. Many keepers feed bottom dwellers in the evening once the lights are off and the faster fish have wound down, which gives the corys a clear run at it.

Keep the substrate clean — a light gravel vacuum at water-change time stops uneaten food from breaking down and spoiling water quality. Corydoras also do best in a group of six or more over a soft or smooth substrate that will not wear down their delicate barbels.

Fit it into the bigger picture

Feeding is only one piece of a healthy tank. If you are still setting up, start with your first aquarium, and keep your numbers in check with how many fish can I put in a 10, 20, 29 or 40 gallon tank.

Written by the team at Tropical Fish Imports in Lethbridge, Alberta. Last reviewed August 2026.

Not sure what to feed your particular bottom dwellers? Tell us what you keep and we will point you to the right food — visit the shop, call 403-380-4506, or send us an email.