10k vs 14k vs 20k MH

[minesinger]

I was told by my LFS that he switched out his 10k MH bulbs for 14k bulbs. I currently have 2-150w 10k MH and 2-65w actinic on my 75g.

What do you all typically run? What's the difference? Will my corals be better with one vs the other? or is it just personal preference?

[westmoorenerd]

I run 14k Aquamaxx's in both a 250w DE and a 175 SE... the difference is most 10ks are white with a little yellow, 14ks are white with a little blue, and 20ks are blue with a little white.... well thats the laymans way of describing it... corals will grow better under 10ks, but color up better with 20ks, with a 14k being a compromise.

[46FiatYamaha]

in general terms the lower the K rating (5500 K is natural unfiltered sun) the better the growth of corals, but more yellow in color. The higher the number, the more blue it gets. Usually around 10 k they are crisp white, and of course 20 k are very blue. But depending on ballast and brand of bulb, there is a range in color and PAR as well, and rarely will Brand A 10K will look like Brand B's 10K. Just for reference, in my gallery I have pics of 250w DE Coralvue 14k bulbs, with a standard Coralvue electronic ballast.

[westmoorenerd]

+1, there are a few 10k and 12k bulbs that actually put out 20k+ of light, and some 14ks that put out under 8k, so the best thing i can say is to check dr sanjays spectrum analysis of different bulbs