Hi everyone, trying to figure out why my goniopora won't open up. Just very intermittently. Tried it in a brighter higher flow area, didn't like it. Moved it down to low flow and light, opened for a few days now closed up again. It's under XR15 pro lights at 40% intensity in LPS mode. Flow from MP40s. Water parameters are good except phosphate is high at .26. Seems to go up and down with feeding Red Sea AB coral food. I have mild diatoms in a 4.5 month old tank. Other corals seem to be doing fine. Should I try it on the sand bed or back of the tank by itself? Picture below show goniopora in right corner of the rock. Thanks for the help.