T5 lighting problem- corals seem to be losing color

My sps seem to be doing well but all my other corals lps mostly seem to be loosing color especially the purple orange red pink and yellow colors, I am currently running a 6 lamp t5ho ati sunpower on a 72 gallon bow front (tanks about 18-20 inches depth) fixture sits 3 inches above water level. All water parameters are checked regularly and all are optimal. Bulbs are all fairly new and as follows from front to back...

Ati blue plus
Ati blue plus
Ati blue plus
Hagen life glo 6500k
Ati blue plus
Ati aqua blue special

SpS more toward back is this reason for aquablue being placed in the last slot

Could it also be that I have been using kalkwasser in my auto top off?? I defenitly realized ever since I started using the kalk instead of TLF two part my coralline algae on my rocks has died out a bunch but maybe this could be because of the lighting and not the kalk, I had better pink and purple coralline growth when I had a 4 bulb fixture that was giving off minimal light due to bad reflectors.... PLEASE VOICE YOUR OPINIONS ALL COMMENTS AND SUGGESTION WILL B GREATLY APPRECIATED!! Thank you

 

Is this your 1st time using kalk? you should get a doser and unless your real familiar with the procedure for makeing limewater i would stay away. Check your magnesium as well as that plays just a big part in your tank as the calcium.

 

What you are experiencing is light inhibition. You only need 4 bulbs with that fixture and you need to move it to 30" above the sand. I would remove 2 of the blue plus and replace the Hagen with a Purple Plus or Coral Plus bulb. Bulbs below 10000K can cause corals to brown out.

 

Bet he didn't want to hear that after spending all that ATI money...lol

 

Ok I moved my fixture up about ten inches off surface and running these bulbs from front to back

Ati blue plus
Ati blue plus
Geisman aquablue 14k
Ati purple plus
Ati blue plus
Ati aquablue 12k

Man I hope this works

 

As soon as I saw that I thought you had "too much" light!