Building a grow cabinet.

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Originally Posted by Roughrider

The problem with small HPS/MH lights is that they really aren't any more efficient than CFLs. A 70w HPS light usually puts out around 5000 to 5500 lumens of light...between 70 and 80 lumens per watt. A 23w CFL from Wal-Mart puts out 1600 lumens...about 70 lumens per watt. I'd try to get at least a 150 HPS.
If you use the 70w HPS, you're still about 15000 lumens short--another reason to go to a 150w HPS. A 150w HPs will put out around 14000 lumens...that's a good 25% more efficient than the 70w HPS or the CFLs.

No matter what...you've got 4 square feet of floor area. Try and get at least 20,000 lumens in there. The way you described, it, you'd have a 70w MH or HPS on with two 200w CFLs. If you mean actual 200w CFLs, like these

Compact Fluorescent - 200 Watt - Full Spectrum 5000K - Energy Miser FE-IIIB-200W Light Bulb

then you don't need any more lights other than two of those. They're 10,000 lumens each. But if you mean something more like this

Compact Fluorescent - 42 Watt - Full Spectrum 6500K - TCP 28942-65 Light Bulb

then you've got 2800 lumens per bulb...you'd need five or so of them with your 70w HPS or MH to do the job right.

If I were you, I'd go with a 150w HPS/MH light. Then, try putting some T5 tubes along the sides and back. Two against the back wall, one on each side. 14w T5 lights put out about 1350 lumens each. You'd get good under canopy light too. Or, you can just hang a couple of sockets with Y-adaptors with 23w CFLs to go with the 150w. Just my .02.

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Now that the ordering woes are over, I'm going to probably swing a 250 watt HPS (maybe 2 150 watt ones). I'll think about using the T5's on the sides also.

You think this would be ample light?

Would a 400 watt HPS be overkill???

A 400w wouldn't be overkill if you've got more than 6 sq. ft. of surface area. In a 2' x 2' area...maybe. You're going to need to be more careful with the light height and ventilation. It's technically true that you can never have too much light...but if your light is too close and your temp goes up, that's bad. Technically, warm air holds more humidity...but with a lamp, extra degrees can dry up your plants, which is hard on seedlings and young plants. If you know you can ventilate adequately and do a good job cooling, you're better off with a bigger light. But I can personally couch for using a 250w in an area of around 2' x 2', or even a little bigger. It will do a great job.

A lot simply depends on how much grow area you've got. If you've got about a 30" x 30" area or less, a 250w will do a good job and (probably) be less of a hassle. I know that some people will disagree...but they're experienced in grows in their areas and know how to deal with extra heat and stress from more light. And, just my opinion here, but...a 30" x 30" area will give you 4 very nice sized plants and a very nice yield. If it's your first grow, or even the first grow in a new area, you might be better off starting a little smaller and working your way through the problems that inevitably crop up. It's not like you'll ever have a problem selling a 250w grow light for 80% of what you paid! :thumbsup:

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Originally Posted by Roughrider

A 400w wouldn't be overkill if you've got more than 6 sq. ft. of surface area. In a 2' x 2' area...maybe. You're going to need to be more careful with the light height and ventilation. It's technically true that you can never have too much light...but if your light is too close and your temp goes up, that's bad. Technically, warm air holds more humidity...but with a lamp, extra degrees can dry up your plants, which is hard on seedlings and young plants. If you know you can ventilate adequately and do a good job cooling, you're better off with a bigger light. But I can personally couch for using a 250w in an area of around 2' x 2', or even a little bigger. It will do a great job.

A lot simply depends on how much grow area you've got. If you've got about a 30" x 30" area or less, a 250w will do a good job and (probably) be less of a hassle. I know that some people will disagree...but they're experienced in grows in their areas and know how to deal with extra heat and stress from more light. And, just my opinion here, but...a 30" x 30" area will give you 4 very nice sized plants and a very nice yield. If it's your first grow, or even the first grow in a new area, you might be better off starting a little smaller and working your way through the problems that inevitably crop up. It's not like you'll ever have a problem selling a 250w grow light for 80% of what you paid! :thumbsup:

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I'm thinking of enclosing my light in plexiglass or lexan or something, using ducting to create an in and out for 2 fans to cool the light itself. Then in the box, have a fan at the bottom sucking air in, and a fan at the top, blowing air out, this should keep the hot air from reaching the plants even more so.

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Originally Posted by maxsuperdanks

I'm thinking of enclosing my light in plexiglass or lexan or something, using ducting to create an in and out for 2 fans to cool the light itself. Then in the box, have a fan at the bottom sucking air in, and a fan at the top, blowing air out, this should keep the hot air from reaching the plants even more so.

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My only worry is the wiring situation, as I have no idea what I'll need to set up an HPS ballast and light, along with CFL's (should be easy for those, they have built in ballasts)