I am just wondering why my purple deaths will not color back up to the beautiful purple that they once were... after having them for about a month they turned to a brown... I have them in two completely seperate tanks one is covered by a 150w MH about ~20" off the light and the other is about ~22" below 4 39w T-5 2 aquablues and 2blue plus'. I feed them cyclopeeze and a mixture once in a while also.