Live Rock turning white

[jwill275]

Over the last 6-8 weeks I've added approx 90 lbs of Live Rock from two well established reef tanks. In both cases the rock was out of the water for less than one half hour. The rock is full of corraline algae and any number of invertibartes. Slowly over time the rock seems to turning white. My tank:
125 gal
2 - Coralife 36" 96w w 10K acitonic light fixtures
Protien Skimmer
Wet dry filter
Water flow from i Korilla 2 and 1 Korilla 3 as well as a rotating powerhead @ 280gph. My intake is a Quietone 4000 - 600+gph.
water change 15-20 gal per weekusing RO/DI
My water parameters are all excellent
salt 1.025 / 34ppm
ph 8.3 amonia 0 nitrite 0 nitrate 0 calcium 320, magnisium 1200 - phosphates recently tested came in at 0.
Can anyone explain why the rock would turn white.

 

[zeroc]

Because the rocks are probably going from a tank with difference light conditions, and a different tank in general, it's not uncommon for the coralline to bleach in a new environment, it'll bounce back eventually. Calcium is a little low though and what's your Alk at?