I am looking for shrimp or any bottom feeder that will help keep my 120 gallon clean(er). i have a few tiger barbs, 3 angel fish, 2 rainbow sharks and a few other non aggressive fish. Shrimp, snails, or fish that will clean up the extra food and if possible, waste. I have been into the fish keeping world for almost 1.5 years but still have many questions about this life style. Any help/feedback would be appreciated.