shrinking carpet anemone

Question
I have had a green carpet anemone for about 5 months. A month ago it started to shrink from about 6 in in diameter to about 2 in. The water must be ok bc I have coraline algae everywhere and my coral is spreading like crazy! I thought it might be the lights going (although they are 6 mo old), so I replaced them. No change. I have 4 54 watt T5's on 39 gal.

Answer
Hi Alyssa. You said in your question that your water must be okay because you have coraline algae and your corals are doing great but what is your water testing at? Are you feeding your carpet anemone on a regular basis? A carpet anemone that is 8-12 inches in diameter will need to be fed 1/2 a teaspoon of food a day. If fed inappropriately it will slowly shrink.  If your lights were going bad, and this is the reason why your anemone is shrinking, it will take a few weeks for it to regrow and start to expand again. It will not happen overnight. T5 lights only need to be replaced every 12 months so if they are only six months old than they were most likely not the problem. My bet would be that you are not feeding this anemone as often as it needs and that is why it is slowly shrinking. The good news is that if you start to incoperate a more frequent feeding regimen the anemone will soon grow and be back to its larger size with in a few months. Try feeding a few bits of clam or chopped silversides every other day for the next few weeks to see if there is any change. The only downside to this sort of feeding schedule is that these anemones can grow large rather quickly with an overall size of up to 40 inches across at its largest. This anemone is much better suited for a tank that is at least 75 gallons with a larger tank being better.