If you would like to add to your freshwater aquarium population but also need help controlling water parameters and organic waste, consider freshwater clams.
natural water filters
Native to temperate freshwater rivers and lakes around the world, the
freshwater clam is a bivalve mollusk that acts like a living filter to help keep aquarium water clean and clear. Freshwater clams such as the Corbicual sp., which originate in Asia and have a brown shell banded in black, help filter your aquarium water by removing detritus and uneaten food from the water column; in doing so, they remove the organic material that would otherwise break down in your system. The end result is reduced nitrite levels and improved water quality.
how to house
Freshwater clams are filter feeders and will often bury themselves in the substrate, leaving only their siphon protruding from the substrate to gather nutrients. A 10-gallon aquarium or larger with a medium to very fine
substrate will provide the best housing for these freshwater bivalves. Be careful not to house freshwater clams with invertebrate-eating fish such as freshwater puffers.
Despite reaching a maximum length of only about 2", freshwater clams such as the Corbicual sp. can have a positive impact on water parameters and may significantly lower nitrite levels.