Purple Death colony is more like "Chocolate Death"

[amppdx]

I was looking back through some old photos of my tank and realised just how brown my Purple Death colony has gotten. The mouth is still nice and green and the skirt has the little speckles, but the disc area is closer to a chocolate brown than the bright purple when i first got it. New polyps look good, but as the get bigger I guess they are gradually getting darker. Any ideas? I have them under a Hamilton 14k, 175W MH, do 10% WC weekly with Kent reef salt and only add a little alk and Ca through the week. They get fed plenty of Rod's and phyto.

 

[reid429]

Vitamin c and amino acid supplement will help a ton

 

[amppdx]

I have been using Reef Plus concentrated vitamin and amino acid suppliment for almost 2 weeks now dosing as per instructions. I think I am starting to see a noticable difference. Thanks for the advice.