Hello! I've been reading on this site for quite a long time-great information! I am reborn to saltwater tanks. Did this about 30 years ago-my how things have changed! I have a simple 55 gallon with all the fixings-nothing elaborate! Fish only-no corals. I started early summer with cycling-no fish for months. I had a healthy tank until I bought a Clown Tang and Coral Beauty at a LFS. Then I had velvet invade-it took out 6 of my nine fish. I was able to save 3-lots of TLC and natural anti-parasitic medication. It's been several weeks and everyone is healthy and beautiful again. I just added 5 various clown fish-hopefully all will go well. I just noticed a pineapple sponge and have a handful of other small, white, circular-almost like a Q-tip sponges (?) on the same 2 live rocks. They're flat though-not like the pineapple sponge. Should I be concerned or is it a healthy tank sign? My water has always been very good-no ammonia, nitrites or nitrates. I test about every 4-5 days and bring my water to my LFS for testing as well. Anything I should be doing that I'm not? Thanks!