Metal Halide

[husker267]

What is the difference between MH bulbs/ballast used in aquaria vs. those used to grow plants indoors? I see all kind of "growlights" on ebay for a lot less than aquarium/reef lighting. Thanks in advance

[griss]

A lot of the grow lights use Sodium or Mercury Vapor ballasts and bulbs. When they do use metal halide, the color temperature of the lamp is much lower than you want for a reef tank...typically 4300K.

With the exception of Iwasaki bulbs (Mercury Vapor), bulbs used for reef tanks require a metal halide ballast and range in color temperature between 6500K to 20000K.

Griss

[husker267]

But, if the growlight ballast was MH and rated lets say 175w....It could support a 175 watt reef bulb at 10,000k...right? - as long as the socket was also correct.

[ron4675]

Welcome to the wild world of Metal Halide!
What you state is somewhat true. If the ballast is a Metal Halide, and the correct socket is used than it should run a say 175w 10k bulb.
BUT the problem is, some ballasts will only run certian bulbs and a certain kelvin. If you try to run different bulbs you'll either get a shorter life, the bulb won't fire, the bulb will explode, or it won't be very bright.
When I bought my setups (one from premium aquatics, and one from marine depot, hellolights is good as well) I got a whole setup that is matched to perform at the optimum life of the bulb. This is the easiest/safest way to get your lighting. But if your into DIY and don't mind doing some research you should be able to match ballast, bulbs, and sockets!

[griss]

As Ron stated some bulbs are designed to run on specific ballasts. A lot of the European made bulbs run much better (better color, longer life, etc) of HQI ballasts. Iwasakis will run on a metal halide ballast, but the color is better on a mercury vapor ballast.

Griss

[white_queen]

So then how do you figure out which bulbs to put with which ballasts to put with which tanks for what purpose?

*scratches head* (well, maybe if I could figure out my convoluted question I'd have a better idea of the answer!) (*grin*)

Angela <><