Which MH Bulb?

[Anonymous]

I am reconsidering the use of MH's over a new sps tank (24" x 18"). I only have room for a single MH pendent. I was considering using a 250 watt 6500K bulb. Will this provide me with a decent color/appearence?? I have no prior experience with MH's and am concerned about buying the right bulb.

 

[Anonymous]

Hi,

6500K bulb would not give you the color and pleasant look. It is very yellow, in fact, i consider it as UGLY. Most people would buy this bulb and supplement it with actinic bulbs. Actually, there is a new bulb with 12,000K. this bulb suppose to give you the perfect white and blue color that reefers have to use 6500K and actinics bulbs to achieve. My next bulb would definitely be this 12000K bulb. The price for this bulb is $98, the price for 6500K is $59. If you buy 6500K and buy actinics bulbs to supplement it, the cost would come out to be equal (give and take a few bucks) there are advantages for using 12,000K though, operating cost would be less b/c you only spend the money on electricity for just the hallide bulbs, not the actinic bulbs. Furthermore, it would dramatically reduce access at the top of your tank, cuz you don't have to try to jamp 4 actinics and two MH bulbs into the same area.

 

[Anonymous]

I am currently running 2, 175watt 14000 bulbs. It is really blue almost to much so, but still looks good. When the time comes to change I will probably go with 10000 bulbs.

James

 

[Anonymous]

I agree with what's been said. I use the Iwasaki 250 W, 6500K MH bulbs (incidentially a very efficient and long lasting bulb) with a pair of VHO's, one white, blue. This looks good to me and the light is very intense and the SPS's grow very fast in this system. I would not however use the Iwasaki bulb by itself, the visual effect is not pleasing. On a tank as small as you are talking about I'd probably use VHO or PC. IMO it's usually best to use at least two MH's together, otherwise all the light is coming from a single point source. Your tank will look a bit strange, and your corals (particularly SPS) may develop strange growth forms, growing toward the light like a plant in a window.

- Greg Hiller

 

[Anonymous]

Milz:
We agree with what Greg Hiller said about the 6500k bulb (even though it's our bulb of choice for propagation at our lfs). However, it isn't very clear what size tank you have with the dimensions you gave - which number is the length, depth, height? This aside, if you have only space for a single MH pendant, you might look into the horizontal pendants. With the horizontal pendants, you will get the maximum output of light from your bulb, as compared to the older style of bell pendants (where the bulb is actually standing on its head). We have two 400wt 6500k pendants over one of our sps propagation vats. As for which bulb, the German 10000k, sold by Hamilton Tech., is a great looking bulb. They don't add any extra blue color to the bulb; the light it gives is more natural - not too blue, nice white. It comes, though, only in a 175wt or 400wt version. HTH - Staff

 

[Anonymous]

Thanks for the info (M.E.Milz is my office address). For the various reasons mentioned,I decided to go with Power Compacts (4x 55 watt). By the way, the tank is 24" wide, 18" deep (front to back), and 20" high (less a 4" sandbed).