I have had a Ritteri Anemone for several years and about 6 months ago it started shrinking. The clowns that host this anemone are still staying with it. It was about 12" across and now it is probably only 3-4 inches. Tank is 180G with Radion XR-15. I have discussed at length with our local Aquarium Shop with no idea of what could be causing this. Anyone help with this would be appreciated.