I have a 25 gallon tank that has been cycled for more than a year with damsels. Two months ago I put in two more damsels, a cleaner shrimp and an orange thorny starfish. Two damsels fought and killed one another. Two weeks later the last damsels died as did the shrimp. I have check and rechecked my water levels. The salinity was a little high at 1.025, but I have been assured by my saltwater dealer that this shouldn't be lethal. I took a water sample to the dealer for testing yesterday, just to see if they found something I did not. Their testing showed that my levels were all fine, except for the salinity. I purchased a yellow tang, a lawnmower blenny and a sea hare. They all seemed fine and were quite active in the tank yesterday evening. This morning, the tang and the blenny are both dead. The sea hare is still alive and the starfish went suicidal and was being sucked in to power head. What is going on? It seems the fish died much too quickly for it to be a disease like ich or such. PLEASE HELP! I did a 20% water change this morning.