Amoania in my tank has im sure overnight shot all the way up to 3.0ppm from 0. The night previouse i installed a large piece of lovely driftwood and a bristle nose cat fish to clear algaue plus a 50 percent water change due to disturbeing substrate. Today i tested and had these results. Very scared now. Have some real nice dwarth gouramis in my tank i dont wanna loose. How can i lower the amonia. I have just cleaned filter wich is a hydor internal.