coraline bleaching...

[Seraphim]

I have been watching my coraline turn white for about a month now. Not sure why. I have sps Some stags caps birds nest and poccillipora doing well ...caps and pocc doing the best....... Everything else in the tanks ...sofites ployps shrooms hammer.....doing ok too. Growth could be better but i bet that is due to my lighting...see specs.. Any idea on the coraline would be helpful. only thing i can think of is my alk flux. i dose coral vite 2x a week and reef plus when i do a water change. 5 gallon wc per week with RC


Specs

40l w/ 20 long sump/fuge with chaeto.
euro reef cs 80 skimmer
mag 7 return
nano stream and korallia 1 for flow
2x 110 vho
2x40 no
2 x 10 ho actinic
temp 80-82
sg 1.025
calcium..kinda high 480
alk I have had a small flux with this 6.8 to 7.5 I am trying to peg 7.2dkh
ph 8.0-8.2

 

[cmador]

Where's your Mg at?

 

[Seraphim]

to be honest....not sure...i dont have a test for it

 

[rj ripetide]

Have you had any real lighting issues or changes?
I went from MH to T-5's and Coraline bleached.
And then again when my lighting cycle screwed up. Both times it grew back just fine. Other then that I can't help.