Help Needed - What Kelvin do I use

[Meaty24]

I have had my tank running for 1.5 years and I have very little coraline algae and my corals do not grow well (granted that my nitrates are too high... 40, and have some phosphate). I was wondering if my lighting is correct.

I have three 400W metal halides and 2 T5 itinics. What kelvin bulbs should I be using? Could that be the problem I have? (other than my water)

 

[125G Reefer]

Your water would be the major issue. Lighting in the 10k range is for best growth. Other than that, your 400w is more than enough.

 

[LunarDDS]

How is your chemistry? Have you checked your alk/cal/mag? Rock solid chemistry and flow is just as important as your lighting. Your 400w is probably more than you need but that is not a problem. 10k for growth and 20k for color is the standard line. I get good growth and color from my radium 20ks. Had good growth and decent color from my 12k reeflux. I ran 10k XM before that but that was when my chemistry was poor and I didn't have my reflectors.