So fix your power heads so the anemone can't get hurt. Not at all difficult:
Hagen Quick Filters. Toss out the inner filter cartridge, and use the housing only. You can adapt them to fit a wide variety of pumps and powerheads with just a bit of ingenuity. The larger one should be available at any LFS or on-line retailer. The smaller ones are more diffucult to find. Tropical Haven in Modesto had them for a while. Not sure if they still do or not.