400 MH and 400 HPS at the same time?

[mrpibb1988]

Hey everyone, I've been lookin up on this and i can't find the exact answer for my situation. I'm growing in a small growbox in my crawl space, and i just purchased one 400 watt MH Sunsytem 5 econogrow and another 400 watt HPS Sunsystem 5. I got glass for both of them and i plan on ventilating the shit out of them so i can keep them as close as possible. I was thinking if i angled the lights towards eachother so the spectrums "criss cross", I could have both reach the plants and have an outstanding grow due to their close distance as well. Lil' help for a newbie would be appreciated! Thanks a lot!

Dino:rasta:

mrpibb1988 Reviewed by mrpibb1988 on 04-05-2006. 400 MH and 400 HPS at the same time? Hey everyone, I've been lookin up on this and i can't find the exact answer for my situation. I'm growing in a small growbox in my crawl space, and i just purchased one 400 watt MH Sunsytem 5 econogrow and another 400 watt HPS Sunsystem 5. I got glass for both of them and i plan on ventilating the shit out of them so i can keep them as close as possible. I was thinking if i angled the lights towards eachother so the spectrums "criss cross", I could have both reach the plants and have an Rating: 5

[Sparrow]

It is not the best to cross beams do to photonreturn. Basically the light can cancel out from what I hear. Best if they are tip to tip. The tip is where the most heat is lost and it will help insulate the bulbs

[mobay]

not good to have the same ratio of lights on your plants. example 3hps to 1 mh will do you wonders. so in your situation you have a 400 watt hps i would get a 125w flouresent light to put in there. lowes have them, self ballasted.

[Sparrow]

What do the ones at lowes look like? Do you know what spectrum they are

[LIP]

Yeah, having two lights together cancell each other out... So it'd be a waste..

If your grow space is small enough, just veg with the MH and flower with the HPS... Simple.

[Jdog7000]

I have 2 1000 watt hps's tilted up slightly at eachother. In a small bedroom.
It's working great. the lights foot prints barley reach eachother in my room, but they do hit a little and it doesn't cancel anything out in my room.Are you guys talking about hps and MH canceling eachother out????
Because my 2 HPS's tilted up at eachother is working so well ,I wouldn't change my set up. It's like 2 suns.Both sides of my plants are always getting full light.And the spectrum penetrates all the way to the floor.

[Sparrow]

I was talking with the president of the general hydroponics chain and he told me that there was a study done at the University of Alaska where to bulbs side by side do to a fanominon called photonreturn can cancel the light out and actually shut off the bulbs. He is extremly techniqel and I was having a bit of trouble following as he uses alot of scientific term but that was the jest of it. Next time I am in the area I will stop in to see him and ask him to explain it to me again. He has explained it to me twice so far but he is very nice and I am sure he would not mind explaining it again. I have to go see him in the next couple months about some thing else so I will keep you posted.

[mrpibb1988]

Good deal, thanks a lot, I'm gonna go ahead and puchase some flourescents for my babies, i dunno if i want to dump the extra money into 2 more HPS, but i'll keep you all posted!!

[dreadydrug]

you've got it wrong, i did waves in physics at the beggining of this year. two waves that arrive in the same place at the same time exactly in phase (same wave length & frequency) will constructivly 'superposition' which baisiclly means the frequency will double.
if two waves arrive in the same place at the same time exactly out of phase (for example one wave starts at the top & one starts at the bottom) it will destructivly superposition, canceling each other out.
here, this might be able to explain it a little better:
http://library.thinkquest.org/C00570...ves/phases.htm

[Sparrow]

Dready drug you are a genius thanks. So seeing how a mirror reverses reflection it would also reverse the wave which is why mirrors make poor reflectors. I think