Live Rock turning white

[AndyMan]

I am noticing my live rock is turning white lately. Any reason why this would be. My calcium seems fine and on the higher end. I do have an algea issue, quite a bit of red algae film covering rocks and sand. I have just started a turf scrubber so I am assuming my tank is transitioning hence the red algae outbreak. The only thing I could assume is Alk is low, would this be the cause?

Salinity ~53 ms
Nitrates < 5 meq/L
Phosphates 1 meq/L
PH 8.0 at night/8.4+ day
Alk: total Alk =2.5 meq/L, Borate Alk 1 meq/L, Carbonate Alk 1.2 meq/L
Calcium 440 to 500
- RedSea test seems inaccurate at 550, LFS tested 440

 

[essmaker]

Have you changed anything recently (before the change)?

Lights different?

 

[BLAKEJOHN]

If the algae was covering the rocks, anywhere that the algae was for any length of time will be white.

 

[jkburton1s]

wait for big al to chime in. he is pretty knowledgeable and may have an answer for you

 

[donj4077]

check you nitrate level and phosphates, temp of tank.

 

[AndyMan]

I don't think i changed anything in my regular maintenance. It's possible it could be the red algae breakout that has settled on the rock...thanks for the feedback.