I did a 40 ltr water change on Monday and after i took the water out i did a bit of cleaning,nanos some smaller rock etc so the water level was about 10-15 cm lower for about 20 minutes.the next day i noticed my coralline starting to bleach and progressively over the next 5 days got worse to the stage where large chunks are completly white.Areas that don't have direct light and Coraline up higher seem unaffected while middle to lower coralline is worst hit.my alk,ca and mag etc are all on the good high side so was wondering if the extra light the coralline received when the water was low has done this.only my 4 24watt actinics were on not my 2 150 MHs.Any thoughts
Last saturday
today