high pressure sodium grow lights page

High Pressure Sodium
Grow Lights

High pressure sodium grow lights are the way to go once you are ready to force your plants to flower or fruit. They are, in fact, just what the doctor ordered. On this page I will help you decide which light is right for you by explaining about different sizes, styles, and options for high pressure sodium grow lights. I also discuss some considerations that come with each of the features.

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At this stage, your plants are craving the yellow/red light of fall...and lots of it! High pressure sodium grow lights deliver both of these things to your plants. The light that they emit is more in the yellow/red spectrum, and so more of the light is a usable wavelength to the plant. It is a WIN WIN for your plants. That is why, no matter what the rest of your garden setup may be, there is always a high pressure sodium grow light for the flowering stage of growth.

What Size Light?

This depends on how much space you have to work with really. See the chart below for an idea of the coverage...

250 watts lights apx 2'x 2'
400 watts lights apx 3'x 3'
600 watts lights apx 4'x 4'

These are only general guidelines. Good flowering and vegatable production happens at around 40-80 watts per square foot. If you have a 600 watt light and a closet with 2'x 3' of floor space (6 squae feet), than simply divide 600 by 6 and you get 100 watts per square foot, in which case you should use a smaller light (or bigger closet). :)

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Hot Tip

During a several month stretch, I had two friends with gardens that were producing more than mine. I was using a 1000 watt light, and they both used 600 watt lights. How you ask? The 600 watt lights produced half as much heat as my 1000 watt light, so the lights could be placed much closer to the plants without heat damage.

Light looses its punch quickly as it moves away from the light source indeed! In addition, not only were my friends using less electric for their lights, they were also using less air conditioning.

Needless to say, I am now looking to trade in my 1000 watt light for a 600. You can see a very helpful page with all of my personal design and setup choices at Jason's Setup.

Distance from Plants

The distance you keep your high pressure sodium grow lights away from your plant tops will be determined by three or four things. They are...

If you have a 400 watt light, keep it at least 12 inches away. Bigger light, bigger distance. I keep my 1000 watt light 24 inches from my plants.

If you have a light with a reflector that is air cooled, than you can move your light a bit closer (especially if you get the glass in the bottom). The bigger the vents and the more direct the air flow through the reflector, the better the cooling benefit will be.

Your exhaust setup is critical. For complete exhaust setup and design advice check out my exhaust setup page. Basically, the bigger the fan, the better. The more efficient the fan, the better. The shorter the exhaust run, the better. By the way, centrifugal fans are the most efficient, in case you were wondering.

When all else doesn't quite cut it, crank up that A.C.! Sometimes (like all summer) there's no way around it.

So Now What?

So now you have a high pressure sodium grow light, but how to use it? See how your light fits into the big picture at my garden design page . Or, learn how to change light cycles and "trick" your plants into flowering at my flower forcing page.

Still not sure about your own setup? Check out my own personal choices at Jason's Setup.

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High Pressure SodiumGrow Lights

What Size Light?

Hot Tip

Distance from Plants

So Now What?

High Pressure Sodium
Grow Lights