SPS lost 50% brown in one day.

[newbostonconst]

I have a Stylophora that I bought a month ago. It has got some brown on the tips the last couple of weeks.
Well last weekend I went away and my lights didn't come on for a day. To my surprise when I got home and found the lights off I thought that was bad, but the coral actually lost a very significant amount of brown.

I am interested if anyone else has seen this and why? It is under good flow and a 250 watt 20K MH.

 

[nycbob]

my only guess is it had too much light b4. they do chng color depending on the light they recieved.