When people come over and see my aquariums they say they seem to be "too clean." I clean them every other week (cleaning the gravel...scrubing the walls for algae, sometimes...doing a 5% water change, mostly.) I have noticed, on this forum (pictures), that other people's aquariums seem to have more algae and stuff growing places (especially the filter area.) Could it be unhealthy for my fish if the tank is "too clean?" Am I doing something wrong?