What I Use For A Grow Light

My grow light of choice for the last few years has been a 400 watt metal halide grow light. It is part of the high intensity discharge family of lamps and operates by sending an electric arc through a tube of mixed gases. They operate by using a ballast and an ignitor to pulse the current to start the lamp. These two components are usually housed separately from the fixture in a metal box. With these lamps you have many options for reflectors. I use a parabolic shade which evenly distributes the light over the area. Now that I have confused most people including myself, here is what it looks like:

The corner of the basement that I use for plants

This is the bulb with some distortion from the flash.

The fixture hangs from a hook that is screwed
into blocking attached to the floor joists. Then the
shade & hanging chains are all attached to the junction box.

This is the remote ballast box.

My current bulb produces 36,000 lumens and consumes 400 watts of power. This compared to a typical 48", 40watt fluorescent bulb which produces approx. 3200 lumens well consuming 40 watts. In other words it would take 11.25 four foot, 40watt fluorescent bulbs to replace the one 400 watt metal halide lamp. A metal halide lamp is by far the most efficient light source per watt and this is why they are used in most retail & commercial settings for lighting.

The main purpose for this light is to over winter plants that I grow outside. I have so many that if I did not have this light I would have plants in every window of the house. It is also a great source of light for growing seeds so it is a win win situation. If I was just using this grow light to start seedlings I would probably go with a 250watt metal halide which would be more then sufficient to cover a 3 foot by 3 foot area and would cut the power use almost by half.

I think the adjustable shelves I added this season will work really well. Previously I was using some rickety wood tables that I threw together and then used an assortment of boxes and crates to position things. I almost knocked by seedlings over a few times so this set up should be much better.

All I have to do is get all the plants under the light and get my onion seeds planted. My next two post will be about starting the onion seeds and showing what plants I over winter. Click this link to see what I have overwintering under the light.