Well,I'm not a mussel expert but here's it goes..I'm very familiar with freshwater mussels,the lake I was raised in had plenty of them,sometimes over 6 inches..but ,,mussels are filter feeders..that does not mean they clean water like an aquarium filter.they don't eat garbage,,,they eat minute plankton and nano larvae floating in the water.there has to be a wave type of movement,not stagnant water,,also be careful..many freshwater mussels are invasive species that can really take over a body of water.whats wrong with that? Well their larvae are parasitic to fish and amphibians..