Oh ive learned through the years of trial and error that over filtration is the only way to go. The only way to ensure a healthy bacteria load is by having 2 large filter systems so that one can be cleaned every couple months. Plus I always put the basket of bio rocks in a pan of tank water while I clean the other filter media. So I don't kill the good bacteria in them, which would completely defeat the purpose of using bio rocks. It also cuts down on the number of water changes I have to do in a year. I've never had a problem with cloudy or murky water.