MH lights - what rating?
 

just wondering what Kelvin rating people would suggest that I purchase for my tank
i have 2 400 W MH and 2 110 VHO Act
it is over a 90 G tank with mixture of coral and fish
should i go with a 10 k, 12 K or 20K
what is the difference really? what would each do for the tank?
Any info would be appreciated
As well, how can i tell what kind i have now..as in a probe start? or a pulse start
basically what kind of ballast that i am running
thanks
Neal

I do not know if this is true becuase i run 14k MH, but I have heard that corals will grow faster under 10k lights but not have the color of 20k lights.

Under 20 K lights color is the best but growth is slow.

I personaly went for looks in my tank when i set it up, coral growth is not to bad.

Maybe other people who have run different bulbs can give there input on color and growth.

I'm debating on choices for new bulbs right now too. I've been running 10Ks, but I'm not happy with the white colour. I Plan to go to 14, 15 or 20K bulbs. I Just need to figure out which. If the corals grow slower but look better, thats fine by me.

Ed, feel welcome to come by and see the Phoenix bulbs I'm running, if you are considering them at all. Really happy with the color, and the corals seem to be doing pretty well.

Neal the K is sometimes just what is appealing to you, and/or what is best for your corals.

I use the 14500K Gieseman Megachrome bulb. It is only slightly blue tinged, but yet the corals fluoresce.:mrgreen:

It is true, there is greater PAR under whiter light. The more blue, the less PAR, and less coral growth.

actually your corals will probably grow better under 6700k lights but they look like crap.

Higher K, more watts. Simple. I have a 16 gal nano with a 175 watt 20k and it looks great, and growth is good (1 polyp candy has grown to 19 polyps in 8 months, 1 polyp torch to 4 polyp in 6 weeks). I am upgrading a 400 watt 20k so I can keep SPS corals (I say Josh's cat's paw and fell in love!) But that's my 2 cents... 20k all the way!

-Pauli

The temperature rating of a bulb has no correlation to wattage. A bulb consuming 175 watts will remain the same regardless of the bulb's kelvin rating.

Personally, I find 20k kelvin bulbs are decent looking on well stocked tanks. If you're running a 'bare bone' tank with not much live rock and corals, then you'll get nothing but glowing blue sand. It is really preference. Take up some of the member's offers and go take a look. It's the only real reference you'll be able to get.

you can get 13k bulbs as well...