I've had this chalice for going on 2 years now and have noticed no growth. On 6/26 I removed all lps from my display due to it being predominantly sps and the amount of flow was bothering my lps. I too this picture the following 2 pics on 6/26 and today 7/11. Check out the growth on the red chalice.
Guess I'll have to move the other now.
Guess I'll have to move the other now.

