Food for bottom feeders: sinking wafers for corydoras, plecos and loaches

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Stock checked on October 7, 2026

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King British Algae Wafer, 40g 8.8 ★★★★★ AcuarioSano rating: 8.8 out of 10 See price

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Fish Tank Aquarium Vegetable Feeder, Bottom Sinking Loach Feeder 7.7 ★★★★★ AcuarioSano rating: 7.7 out of 10 See price

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Why bottom feeders need their own food

Flakes float and get eaten within seconds by tetras, guppies and barbs. What little reaches the bottom is usually dissolved or simply not enough. That is why corydoras, plecos and loaches need food that sinks fast and holds together for a few hours: tablets, wafers, chips or sinking pellets.

Assuming "cleanup crew" fish live on scraps is one of the most common mistakes. A panda cory is an omnivore that hunts small invertebrates and debris in the sand; a bristlenose pleco rasps algae and biofilm and also needs plant matter and driftwood. We cover this in detail in fish that clean the aquarium.

Algae, protein and wood: what each one eats

Fish	Diet	Staple food	Extras
Corydoras	omnivores leaning carnivore	sinking tablets or pellets with animal protein	frozen bloodworms, brine shrimp
Bristlenose and otocinclus	herbivores	algae or spirulina wafers	blanched zucchini or cucumber
Wood-eating plecos (Panaque, Panaqolus)	wood eaters	driftwood in the tank + veggie wafers	vegetables
Loaches (kuhli, clown)	carnivore-omnivores	protein tablets and pellets	worms, snails for larger species

Algae or spirulina wafers (Hikari Algae Wafers, Tetra Pleco, Fluval Bug Bites bottom feeder formula, Omega One and similar) are the staple for herbivores such as the otocinclus. Protein wafers (shrimp, fish, insects) suit corydoras and loaches better. In a mixed tank, alternate the two or use a blend.

When and how much to feed

Many bottom feeders are crepuscular: the kuhli loach and most plecos become active when the light drops. Drop the wafers in shortly after lights out so they reach the intended fish rather than the mid-water crowd.

• Amount: as a starting point, one small tablet per 2-3 corydoras, or one wafer per adult pleco, then adjust based on leftovers.
• Frequency: once a day, or every other day if they also eat scraps from other foods; one fasting day a week.
• Remove leftovers: if soft wafer remains the next morning, you fed too much: siphon it out.

Substrate, barbels and water quality

Corydoras find food by sifting the substrate with their barbels. Sharp or dirty gravel wears them down and they get infected, so fine, rounded sand is ideal, along with vacuuming the bottom during your weekly 20-30% water changes. Wafers rotting in the substrate release ammonia and feed bacteria that make things worse.

For herbivores, fresh vegetables are a great extra: blanched zucchini, cucumber or spinach held down with a veggie clip or weight. Remove them after 12-24 hours before they break down. Check general portions in how much and how often to feed fish.

Common mistakes

• Assuming bottom feeders will live on leftovers.
• Feeding corydoras only spirulina, or a bristlenose only protein.
• Dropping wafers in with the lights on so other fish eat them.
• Leaving uneaten wafers on the bottom for days.
• Keeping wood-eating plecos without driftwood.

We compare spec sheets, verified reviews and real-world use criteria, but we do not physically test the products: use the products above as a starting point and check each listing for the main ingredients and the wafer size.