Thanks for all the advice. I hope that now that the "beastie" is gone I won't have any more problems. What would happen if I decided to just let the aiptasia multiply?

Today the largest group of zoos I scraped off the rock looks really good, only a few tentacles open on the smaller colonies and the smallest 2 groups are totally closed up.

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To the best of my knowledge aptasia are like weeds, that spread and use up valuable territory, they will multiple until they choke the life out of your tank much like the common thistle. And they look bad.

Die aptasia Die!