I have a 30 gallon saltwater tank. It's very basic, did have some liverock but I took it out to treat the tank. It has one large tomato clown and 2 damsels, and a few hermit crabs. The tank cycled for a month before I put the damsels in it. Everything was fine, no ammonia, nitrates, nitrites , etc. About two weeks after I put the damsels in it, I put the tomato clown in there. For a week everything was fine but then a week and 1/2 ago it started having a major ich problem. I treated it 3 differnt times, did a water change, and nothing changed (the ich actually got worse). I tryed a new ich medicine for a couple treatments and it disapeared so I did a water change and put the carbon back in the filters. Then a day later, I woke up in the morning and they were covered again. I checked all parameters of the water and took a sample to the lfs and everything was still fine. What is going on?! The ich has cleared some again since I started back treating it.