Snails will usually find enough left over fish food, algae, and live plant material to eat. If you need to supplement their feeding (like in a bare tank), you can feed lettuces like romaine, kale, or cucumber (split, remove seeds, attach to something heavy to sink). Only provide as much as they will eat over a day. Each day, remove uneaten portions.

A one inch snail might eat a 3" x 2" piece of romaine once every two days as an example. Snails do not need fresh vegetables daily unless there are a lot of them or they are large like apple snails. One keeper of apple snails reports that five 4 cm apple snails (P. flagellata and P. glauca) might eat one big lettuce leaf in a night. Snails will also eat the sinking tablets made to feed bottom dwelling fish and plecostomus. There are a number of algae-containing tablets for algae eaters like plecostomus that work well as well as Tabi-Min by Tetra that is a sinking food pellet.

Good Things About Snails: Some species eat algae. They will clean up leftover fish foods. They will eat dead plant and animal materials, thus cleaning the tank. They may burrow through the substrate and aerate it (mostly just trumpet snails do this). They do not harm live, mobile fish. They are interesting in their own right and part of the ecosystem.

Bad Things About Snails: Some species may eat plants. If they multiply too rapidly, they could die off. Their corpses would be a major pollutant and could poison other animals in the tank or pond. Large snails can create copious amounts of waste adding to the nutrient load. Snails may eat fish eggs or newborn fry. Some specimens may harbor parasites and other ailments which could be passed on to fish.