Metal Halide lights

[houguy]

1. How far above the top of seedlings should the metal halide light be? (e.g. higher than would be the case with fluorescent tubes?)
2. Anybody with experience using these have interesting comments? I scrolled through 7 pages of this forum and didn't see mention of either metal halide or HPS lights.

(Note: what attracted me to the metal halide light was the fact that it covers a 3.5 x 3.5 foot area.)

[Doug9345]

I'll bump this up even though someone answered you in another thread. You might get more input.

[AKmark]

I use HPS lights and they are much better than MH's, both have to be at least 2ft from plants.

[dpurdy]

houguy,
I use metal halide lights as well as fluorescent lights. I use the fluorescent tubes during the early stages of growth and switch to metal halide when they get a few weeks old. Usually when I re-pot I switch to the metal halide because of the amount of space that the pots and plants take up. Depending on how many plants I have growing, I decide on which size metal halide light I use. I have a 1000 watt and (2) 400 & 250 watt switchable fixtures that I can use. The distance between the light fixtures and plants depends on the size and amount of heat that is being put out. A 1000 watt light will produce much more heat than say a 400 watt or 250 watt, and some experimentation will be needed. The problem with using a HPS type light is that the light spectrum will force your plants to flower early and fool your plants into producing fruit. You don't want that to happen. PM me if you would like some more info on my set up and fixtures. I'm in the process of setting up the nursery this week and will set by mid week. The one drawback from using the larger lights is that they are a little more expensive to use than say florescent fixtures.
dpurdy

[AKmark]

Originally Posted by dpurdy

houguy,
I use metal halide lights as well as fluorescent lights. I use the fluorescent tubes during the early stages of growth and switch to metal halide when they get a few weeks old. Usually when I re-pot I switch to the metal halide because of the amount of space that the pots and plants take up. Depending on how many plants I have growing, I decide on which size metal halide light I use. I have a 1000 watt and (2) 400 & 250 watt switchable fixtures that I can use. The distance between the light fixtures and plants depends on the size and amount of heat that is being put out. A 1000 watt light will produce much more heat than say a 400 watt or 250 watt, and some experimentation will be needed. The problem with using a HPS type light is that the light spectrum will force your plants to flower early and fool your plants into producing fruit. You don't want that to happen. PM me if you would like some more info on my set up and fixtures. I'm in the process of setting up the nursery this week and will set by mid week. The one drawback from using the larger lights is that they are a little more expensive to use than say florescent fixtures.
dpurdy

I have no problem with early flowering, and grow hundreds of plants. HPS will perform like no other, check my 2013 AK greenhouse thread in container gardening, all plants were started under HPS lights.