wonder why?

Ok! my tank it's been up and running now for over 8 weeks exactly how many, im not sure, could be 10?! I check my parameters some what often, don't have much livestock few fish and live rock already cured. my CA it's been 500 to 520ppm's for the last 2-1/2 to 3 weeks my DKHº 12º to 13º and everything seems to be ok, other than my live rock which i know that is starting to loose the purple, and pink color, fading to skeletal white.
has anyone ever experienced this before? by the way i have a 55g tank!

Thank you in advance

 

what is the mag level?

 

don't have a test kit 4 it yet, can you advice of a good one., i mean accurate?

 

I think that your Cal is high, the norm is between 400-460ppm. If your planning on a reef tank, you need a Mag tester. Luna

 

if the mag is low it will cause the calcium to be high right?

 

thanks again! i be working on getting one soon.
I do believe that i read that some where, or is it the dkh?