how far from tops of plants?

[Guest]

Hey guys. I just installed my new 400 hps in my grow box and was wondering how far most of you guys keep the bulb from the tops of the plants. Just trying to get an idea what to shoot for. Right now it's at about 10 inches.

 

[Closet Funk]

I'd say no closer then 8 inches for a 400. I got a 250 and I can keep them as close as 5 inches. Have a fan blowing at the bulb to keep it cooler.

 

[JLP]

If your hood is air-cooled and the plants are not seedlings you can have about 6'' off the canopy usually,if the leaves start bleaching,move it up.

If the hood is uncooled or if the plants are seedlings then 10''-12'' is probably acceptable as long as you have a fan moving air around the plants and light.

JLP

 

[Guest]

Like closet funk said if there is a fan blowing on the bulb, 8" is fine. If you get an aircooled hood. Depending on the blower you use, you could get them as close as 6".

 

[Guest]

air cooled hood and 400 kick ass!! i keep a 1000w hps aircooled at about 12"-16"

 

[bostrom155]

I can do about 3 or 4 with out bleaching, but my question is what is a tolerable maximum you would go and still be happy with yield?


I'm pushing 18 inches on each side of my 400, thier about 37 or 37 inches across.

 

[Mad HattersWrld]

like the tube, is that only one 400 in the whole space?

 

[bostrom155]

like the tube, is that only one 400 in the whole space?

Yea this one 400 is gonna have to do for a while, I guess i'm stretching it a bit

 

[Guest]

Thanks guys for sharing. I can't wait to see the plant/yield difference from my old 250 to the 400. Wish me luck.

 

[bostrom155]

Thanks guys for sharing. I can't wait to see the plant/yield difference from my old 250 to the 400. Wish me luck.

Yea good luck it will be nice, i'm coming from 3x150's

 

[Opt1983]

Average joe, Yes it depends on if your using a air-cooled hood or not. If you aren't...like me, i keep mine right about 10.5 inches. Any closer, and u can tell the difference. If you really wanna get the most outta your light, make sure u do some type of LSTing , topping , watever floats your boat, that way you have more quality tops (colas) close to the light to minimize them damn popcorn buds! -Opt

 

[minds_I]

I have to agree-some of those buds on the out eadges could be trained closer. Just my thought.

minds_I

 

[bostrom155]

I have to agree-some of those buds on the out eadges could be trained closer. Just my thought.

minds_I

minds I is that for me? If so, I'm trying to figure out keeping 8 girls in the white/clearish rectangle 3 gal pots i'm using. The pots are 9"x7", so length wise it's 29 inches, so the end plants are 15 inches from the light, I propped the outer plants up higher to catch the light. I rotate often, too.

Whats some training ideas, I'm mostly topping now, done scrog.
How many plant are you guys getting under your 400's

 

[Guest]

Good luck, with going from 250 to 400 watts. Thats should be a lot of fun, at least it was for me.

 

[minds_I]

Bostrom,

Yeah, maybe turn the outer plants so they are closer to the light.

".....go into the light..."

I my cabinet, I rotate my crop to try and achieve an even ligth distribution of=ver the course of a grow. Although, as some plants grow it becomes apparent which buds to favor with the light.

minds_I

 

[Guest]

Hey everyone, I read that 400w HPS usable light is 2 1/2 to 3 ft. max. So if 10" above plant= 20" plants, but of corse no buddy leaves the low branches on so 20" from your lowest leaf is what I do. Like MIND_I said Rotation of plants is the key always put tall plants in corners or around outside if in a circle, short plants right under light. This keeps the light as close as possible(stadium seating) tall plants can be bent and staked where needed.If not sure about height of light use your hand and feel if warm not hot.Also I read that they sell a light METER for like 15 bucks,that lets you get exact readings from bottom of plant Maybe someone else will chime in on this. good luck

 

[Guest]

I just added an extra 4" computer fan blowing on the bulb. Using the back of the hand trick, I can get them 6" under the light. Although I have them at about 8".

Today is day 3 flowering of my nl2 (oasis) and dp strawberry cough. I'll try to snap some pics today.

 

[bostrom155]

Minds I thanks man, guess i need to wake up...lol

heavy THC, staking is a good idea, thanks

I dont like the plants 15" away with my 400

 

[minds_I]

Its all good.

minds_I

 

[Tarbosh]

how do you wire a computer fan to blow on your 400? with a battery?