Acropora Sunburnt?

[svavrek]

I had purchased my first SPS frag that was about 1" tall back in May 2013. Figured why not try it - it was only 20$. It was a green Acropora of some sort and was doing really well... Now it is November, and the coral is still going strong and is now about 3" and branching a bit. New growth no problem. I have many other SPS frags now that are taking off like crazy... This acro though has turned brown in the beginning of October - right when I put my new Maxspect R420r on top of the tank. I upgraded from a little 1W Marineland "Reef Capable" POS LED light... for the first 2 weeks I ran the blues at 80% and whites at 30% and today the blues are at 100% and whites at 50% only. Every other piece of coral is doing great but this acro turned brown and I cannot get the color back... Any ideas? My params are great and the tank is thriving otherwise. I do dose Aquavitro 8.4 and Calc, and twice a week use Fuel and Nutri/Cell on Thursdays - the day before my water changes.... I should add that the coral was doing awesome under the crap Marineland LED light...

Water Parameters:
dhk: 7.7
SG: 1.024-1.025
pH: 8.2
Calc: ~450
Mag: ~1450
PO4: zero
NO3: zero
NO2: zero
Ammo: zero

Tank is a 46 bowfront, light above, 10g sump w/ PSK-75 Skimmer and Refugium. Weekly (every Friday) 5 gallon changes and daily top-off.

 

[Relativity]

It may have grown more brown zooxanthliea to compensate for the lack of light you gave it

 

[svavrek]

So maybe, even though the razor is better, I still need to use the old marineland led too?