lighting Q's

[ZooYorkUnderworld]

ok I have my 15g with 150w hqi hanging over it. My reef buddie has 24g ap
with plain ol' pc's. we both use the same water( I have the ro-di unit) we split rock in a gb, both dose 2 part. My question is why do his Zoa's grow so quick under pc's and mine grow very slow under mh's? I am almost tempted to go to the t-5's just for growth/color purposes but at the same time I am baffled as to why under pc's his zoa's grow so well? I have all softies mostly zoa's what do you guys think I should do? just to add some info
bulb-20k ushio
ballast-m81
age- 3months

 

[msman825]

I get better growth from 10k med growth from 14k and little growth from 20k my self

 

[ZooYorkUnderworld]

color temps I understand, but why would any pc lighting compare or be better then any type of mh? you would think that mh's no matter what kelvin would surpass any pc, no?

 

[JeffReef]

I think MH has an edge over light output when compared to PCs. But light spectrum is another story. With 20k, you're eliminating most of the red, yellow and green spectrums - all of which are vital to coral growth. Thus, a 10k PC of lower intensity MAY be a better choice for growth than that of a 20k MH.

I used (2) normal output flourescent bulbs, (1) 20w 100% actinic and (1) 20w 65k, for 14 years and grew LPS/softies. These bulbs were not bright at all. But it worked because I was able to provide a broad spectrum of lights to my corals.

Just my 2 cents. I have no scientific study to back up claims. :happy7:

 

[ZooYorkUnderworld]

thankyou, that does make very good sense to me...