what is it?

I have a 55 gallon salt water tank with a UV filter and external filter system. All has been well in the tank no issues and fish are healthy! No corrals in tank, 10 fish. Can you help me identify what is growing in my tank, is it bad or just normal??? See pictures below in file. Thank you in...

Hey all, my frogspawn coral frag got moved to larger tank. I think he was picked up roughly with forceps during the move (grr) and a couple days later looks like this. Is this damage from the move, sting from the duncan, or something else going on? Hes not a happy guy. What should I do? Thanks!

So I was tearing down my 50 down and I found this guy in my sump. He is about 3" long 1" wide and flat. The pics are taken in a five gallon pale.

Yesterday I purchased a 2lb piece of live rock with some orange zoo's on it. When I put it in my tank I saw what looked like a small slug or a snail with no shell crawl out from under the rock. It was pretty non-discript: Sort of translucent greyish/white just under an inch long. The backside...