frogspawn Help. So confused

[ChitownRomeo]

Ok i need some help cause I am stumped. I have had this colony of frogspawn for about a year. it has about 12 heads and 6 of them open well and 6 only a little. When a do a water change within 4 minutes ALL of them open very very wide. I mean the best polyp extension. The next day, the same 6 heads will not extend at all again. what the heck can happen when the lights go off and back on that these heads won't open back up. I have 6 True lumen Pro Led strips over the 55 gallon tank. 4 Marine fusion and 2 deepwater blue all 48 inch. Maybe too much light? Just can't understand why they look like crap until I put the new water in and next day back to looking like crap. All the other corals are looking good. No brown jelly or nothing. this has been going on for so long. I'm so confused.

 

[Oxylebius]

Since the coral is reacting to water changes, I'm wondering if it is reacting positively to a change in chemistry of the tank. What are your Alk, Ca, Mg, Nitrate and phosphate levels:
1) before water change,
2) after water change, and
3) the next day