I'm very surprised how sensitive this coral is to PO4. I've been a little short on funds and have been doing minimal maintenance. I found my phosphates at about .05 today. We never shoot for zero, but when they reach today's reading this coral doesn't fully expand. This has happened before. Caught it a little earlier this time. It also likes newer lights, high NO3, and higher dKH. My CA tends to run over 500, which is fine with this LPS, too.