Torch partially bleached

[bigmayreefer]

I got home tonight and found that 2 out of 4 heads of my torch have bleached out. These two that have lost color just finished spliting. Is it a phase or are they disliking the light/position? it has been in the same place since i bought it a month ago, and my water has checked fine with the only measurable reading a 10 in nitrate. Any suggestions would be appreciated.
Thanks in advance.