So about 2 months ago we adopted a reef tank. We had experience in the past with fresh water and some salt water tanks, but not reefs. Before adopting this 55 gallon tank my fiancee's dad combined it with a small tank he had. Everything seemed well except for a tree like coral who turned grey and shrunk. We weren't sure the
salinity was being read correctly with the
hydrometer so being vet techs we took a sample to work and tested it on the refractometer. The refract. was reading low so we tried to slowly raise the
salinity with 10% weekly water changes. Now 2 months have gone by and the little tree guy is looking good (which made me think the water changes might be working). Not convinced the
salinity was still right we took a water sample to the local fish store and when they tested it with their refract. the results were the same as our
hydrometer. Doesn't make sense to me. A refract. shouldn't differ from one to another since all it does is compare the
specific gravity of a sample to that of water. So now the
salinity is fine, higher then it was, and the tree is still surviving but for the past week to week and a half our leather coral has turned purple and shrunk. A few days ago this neon tetra (we call pig fish) has been swooping down and biting and pushing it all over the tank. I thought maybe the coral was shedding, but now I am wondering if the fish knows something i don't. Like is it dying. Did we cause it even though everyone else looks great. Sorry I kind of babbled in this post but i am really frustrated and would like to save this guy if I can. I tried to upload pics but my files are to big. If anyone has any suggestions it would be a great help.