Is it possible for aiptasia to appear from seemingly nothing? I have an 8 month old tank that is nearly fully established (rock is fully green, and has a bunch of purple spots) and had added no live rock or coral since april. when doing a water change recently, I noticed on the base of my HOB protein skimmers pump, there was a tiny aiptasia growing on it, yet there was none anywhere else that I could find. The last coral I added had no aiptasta, and the others I had checked when I bought them with none on them too.