Polyp colony getting smaller. Suggestions?

[Komerider]

Hi all, my polyps seem to get smaller and not open over time

I think light, temp and water quality are ok.

Running zetlight 6600 (same as pacific reef main tank), 26-27 degree c, around 10 on nitrate.

Other corals including elegance,hammerhead, plates etc np and growing.

Any suggestions? Met a friendly who recommended a dip to eliminate possible parasites. Any other possibilities?

[leejwa]

Try target feeding it