Added my first fish to my tank after it cycled. It was a clown fish . Noticed some white spots and a couple of days later the fish stopped eating so I treated it with ich attack. The fish died a couple of days later. How long should I wait be for I add another fish? I have some snails an hermit crabs in the tank now. I have been checking all my levels with my test kits and they are good. I have a 75 gallon tank with 90lbs of rock.