How long have they been in this tank for? Have they always had this coloration? The sps aren't bleached, they're browned out compared to what they were. Raising your lights wont help all too much. I'd focus on lowering your nutrients instead. Has this just happened since you've started doing zeo? If so, what zeo supplements are you using? I'd only use zeobak and a carbon source in the beginning. You don't need the amino acids and coral foods until you are lacking in the nutrients that they provide. But that's just me.
they have been in this tank around 1 month and i have just changed my lighting for around 2 weeks ago . even before that they have been introduced, i have been using zeo
my no3 is 0 (salifert) , po4= 0.003 (hanna Hi736)
dkh = 7
mg=1200
ca= 400
so i do not understand is it due to insufficient lighting ?
You wouldn't want your DKH that high using Zeovit..I'd also recommend getting your alk a little closer to 10 dkh and even raising the mag to around 1350'ish. Ca looks good to me.
+1..chercm,
there's no way 1 week of insufficient lighting would do that to your corals. In natural environments it's normal to have cloudly days that last a few days up to few weeks, also insufficient lighting normally lead to browning of the corals, not pe retraction.
I'd look at the following first:
1. Water parameter, your kh seems okay, but mg a little low, try to aim for 1300ish.
Looking at your previous posts, you also seem to have cyano problem, was that resolved?
2. You also newly switched to zv system, did you overdose any of the biology line (food, bak, start, etc.)? The reaction to the corals seems like they're reacting to the water chemistry more than lighting.
2. Lack of acclimation is also probably why, you went from 2x 250w mh to 2x 160w led, you should try to turn off the 30w bulbs also try reducing photoperiod, and let the corals have time to acclimate to the new light.