Bleached coralline

[Swampy]

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

[rollergirl]

Hey I'm hardly the expert on this, but when we moved house and the rock was semi-exposed whilst emptying, filling the tank etc, it went all bleached exactly like that afterwards, but in about a weeks time it all came back with a vengeance. So hopefully yours will too?!

[Swampy]

cool.No more water changes with the lights on then. :roll:

Coralline was just starting in my tank and this has gone and set it back.Blah :-?

[wasp]

My coraline sharply stops at a line a few inches below the water surface, the level the tank gets drained to when I do a WC.

Although it looks like all your coraline is bleached, even the low down stuff? The other biggies to check are kh, not too low, and phosphate, not too high. Did you use NSW or ASW?

If Mg goes 1600 + it can interfere with coraline.