MH 400W and Heat...
 

I am seriously considering the purchase of a 400W Metal Halide lamp and moving my windowsill culture to a grow area in my basement. In fact, I will begin growing under lights starting this Fall.

My summers are pretty conducive to outdoor orchid growing, so I figure I'll summer my phals outdoors while planning and preparing my indoor grow.

My preference is a 400W Metal Halide light as opposed to t-5 HO fluorescents. Right or wrong, I think that MH is a better grow option. The only concern that I have is the heat that MH's generate. I understand that they can get quite hot and many use "exhaust" fans to dissipate the heat. I do not want to implement or utilize an intricate exhaust system just so that I can operate a MH.

Do metal halides in fact require a fan exhaust system? Are there ones on the market that minimize the heat such as the ones with the digital electronic ballasts? Do any forum members grow under MH without using an intricate fan exhaust system?

Your thoughts on this topic are appreciated.

if you're just growing Phals a MH seems like it would be overkill. Just stick with regular fluoros; I use regular t-12s for for Masdes and phals

A couple of things to keep in mind with MH - yes, they do generate a lot of heat, but if yours is an unheated basement (mine is, up in Doylestown), that may be good for phals. Don't forget that they like it really warm.

Also, you'll want a remote ballast, as that generates heat too, and heat shortens the lives of all components.

The hot fixture is a burn hazard, as well, so either get one with multiple walls to shield it, or get a fan to pull the heat away.

One nice thing about a MH versus fluorescent is that the light - being so much more intense - can be farther from the plants, giving you more working space.

On the other hand, the color rendition when under the lights will not be so great, but if you're like me and bring plants into the kitchen or other living areas of the home when they are blooming, it doesn't matter.

When you make up your mind about what you want, contact me, as I'm a Hydrofarm distributor, and typically discount their prices - AND, being in the area, can probably keep shipping cost to a minimum.

Ray, you make some good points, but you can probably get the same benefits from a t5 set-up, while diminishing some of the issues with excess heat

No argument here! For the few instances in which I use artificial light, I am using T5's.