I was fortunate to avoid a tank crash when one of my anemones crawled into a power head and decided to shred himself to pieces. Of course this happens the day I leave for vacation and only have time and enough water to do a 15 gallon water change. I think running a lot ROX .8 carbon saved my tank from a crash. Side note, I have one anemone now and it is becoming a royal pain as it likes to change places in the tank every week or two and sting any coral that I decided to glue down. It doesn't help that the anemone is the size of a beach ball. I have resorted to moving live rock around to see I can contain its location to some extent.