Small cab grow with 400 watt hps?

If I build a cooltube, could a 400 hps work in a cab thats 25"w x 19 "d x 36"h? Would the top of the plant get bleached out if it's too close, just from the light? I have a 150 on the way, but was thinking maybe 2500 or 400 w/cooltuibe?

remember you cant have the 400 hps closer than 12 inches.........this is a fact from a growing bible

Thanks for the reply! is that because the intensity of the light will hurt the plant? I've heard about people with cooltubes that have plants touching the glass and not hurting, but perhaps they had 150's or 250's? Do you recall the distance required for a 250 hps?

if you want the lights close to plant then use cfl lights not hps which will burn your plants if to close

CFL's will burn the plants if they are too close, too. With a cooltube set up correctly I think I could have at least 250w hps in there and the plants could be 1 to 2 " from the glass. I 've heard folks say they move the plants around once a day or so to prevent bleaching but that it will work!

I would do the 250hps in a cooltube for sure. With remote ballast and cooltube it would be the most you could get away with in there and is sure to put out more than cfl's could. 250 yes, 400 I just don't think so but you could prove us wrong maybe. Must remote ballast and cooltube either way.

People that stack 6x42w cfl's in a little box are still putting out close to the same heat as one 250 even without cooltube except without you better stay 4" away from the plants and have a very good fan.

ok so i disagree with oregonmeds for sure. Go with the 400 and cool tube it. Also you can have plants as close to the light as they can get as long as it is cool enough. Some peoples cooltubes are cool enough where the plants actually touch the glass. And that is a FACT.

leojapsky said:

remember you cant have the 400 hps closer than 12 inches.........this is a fact from a growing bible

Click to expand...

Jorge says that because he is talking about HID lights that are not cool tubed. A HID light emits alot of heat without the tube. When you are not using one than you need to keep with the 12" rule.

36 inches is a little close... but what you could do is scrog method or lst... check it out.

Yea Im voting for 400

You can boost cfm until its cool enough. 60% more lighting means 60% more nug.

btw, to answer an original question, bleaching is very difficult to do.

The distance references are for heat purposes, not light exposure

In that case it's all about cooling the bulb. a cooltube situation is the best then, as you get tons more light (higher wattage lamp) minus the heat. I've got a vent at the top of my closet where the cab is that vents into the garage. I'll run about 4 feet of flexible ducting up to that, maybe put a small fan in front of the duct outlet to help exhaust the heat and the grow closet should stay nice and cool. Say, 150 cfm fan inside the grow cab to exhaust the cool tube?