I''ve had a salt water tank for a little more then a year, so I am some what new to the game. I started with totally dead live rock and sand and even boiled the live rock before I started a year ago. I haven't added any new fish to my take for at least 6 monthes. Now I have started seeing thing in my tank that I have never seen before. I have accouple bristle worms in my sump tank (not too worried about them since my fish would eat them if they made it to my tank) by i just got my first aiptasia. Where would these come from. I just use frozen food so the only way I could see them being added to my tank would be through water changes. I always buy my water (salt and ro/di) from a local fish store. Is it possable to get aiptasia from the fish store's water?