Water Changes and Frags on High Frag Rack

[Diesel48]

This may be a stupid question but when doing a water change I usually change out 26 gallons of a Red Sea 750 XXL (160 Gallons). I have a few new frags that when the water is low is right at the surface of the water. Should I be turning off my lights or make them dimmer during the change? Seems like there is a chance they could get toasted but I am not quite sure. I ask as I have a 3 week old frag of PC Rainbow. The first couple weeks it looked good, I did a water change and noticed that it was almost sticking out of the water. A couple of days later and I can see that the tips were getting lighter, then came filaments. About a week later all of the tips do not look great. I am trying to determine if that was the cause or my tank just does not like PC Rainbows. I have a few other acros that have been growing and looking good for about 4-6 months now.

Tank is 2 years old March 20.
Alk 7.4-7.6
CA 440
Mag 1350
NO3 8-12
PO4 .2 - .3 (a little high but should not kill anything) I started up my cheato refugium about 2 weeks ago. Only other filtration is a skimmer.
Bare bottom, started with dry rock.
Kessil 360X / T5 Aqutic life Combo, 4 blue + Bulbs. 8" off the water, t5's 9 hours a day, 2 hour ramp up to 95% on the kessils. Peak to 100% over the course of 5 hours, come down to 65% for 3 hours then ramp down to 0% the last 2 hours. Par ranges all in the tank 250 - 375, nothing to extreme.
Dosing 45 ML of BRS Soda Ash and Calcium daily to keep levels
30ML of live phyto once a day

 

[dbowman5]

you may be correct depending on how long your water change took and what par levels were reached during it you may have distressed your frags