Positioning my 150 w HPS

I would like some advice on the height of my Sun Systems 150w HPS. This is a 2 x 1 x 3 tall cabinet. The current height of the light is about 10 inches. My canopy is a consistent 82 degrees F. I lowered the light a few inches because I feel that growth has slowed a bit since I switched from 6 CFL's, but I also repotted at the same time. I have a fan on the canopy and the plants seem fine.

With HPS is closer better? If I go higher I get a better disbursement of light I think.




It's kind of odd with this small light and the ballast built in. I have to move it more to one side of the box to keep the actual bulb in the center. I am thinking that in my next cab I may design the depth so I can spin the fixture 90 degrees and see how the light disperses then.

Maybe I'm being to anal about it.. Any thoughts or suggestions besides get a 400w dimmable ballast and air cooled hood? That's my next project. I want to finish what I started for now.

Thx for the advice..

One more question.. I'm considering building a slightly larger cab. About 3 or 4 sqft. If I design it to be 6 or 7 ft tall will this help with heat elimination and disbursement? Seems like it would.

Thx

1) a 400w light would be way too much for that space,so would a 250w HID.

A 150 is the right amount if light for a 3 square foot area (50w to 66w per square foot is optimal).

2) It's about finding the equilibrium of light spread and canopy temp.

I've got that same light and always kept it about 8-12" above. It is a hot little light but it works pretty damn good.

I got a couple 4" computer case fans and an old answering machine power adapter and made a fan kit that mounted to the light & ballast vents that helped with cooling. and 6 CFLs will veg nicely.