yeah... just started out. I have a few fish (goby, tang, and two clowns) and a few hermits... maybe 3 or 4. Ive been doing water changes periodically but only about 5 gallons at a time or so. So more often? Or more water removed? Or a bit of both? Lights are running about 12 hrs a day... 4 or so hrs being actinics only.