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 outstanding grow due to their close distance as well. Lil' help for a newbie would be appreciated! Thanks a lot!

Dino:rasta:

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

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.

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

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.

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.

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.

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!!

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

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

Allright one more question, I plan on growing around 16 plants, 4 x 4 in 2.5 gallon buckets, how many watts would be sufficient to grow some dank buds. I was planning on doing the MH and HPS, but i guess i'll have to reconsider. If i have to go out and buy more lights i for sure will, thanks a lot guys!

A 400 watt should be fine. Rotate your plants every few days. I had a 400 tracked and 50 mothers two feet under it. I like MH myself.

Allright good deal, i have MH and HPS both 400 a piece with the econogro built in ballast, so i'm gonna roll with my MH for veg, then blast them with the HPS for flowering. I'm gona swing by lowes and see what kinda flourescents they have for some supplement lights. Thanks again everyone for your help! Would have made a big mistake otherwise!

cool white or full spectrum are what i use

Hey dreadydrug, i have a quick question bro, i read that link of yours about the constructive and destructive types of interference and from what i snagged from it was that if you align the wavelengths just read they'll doublke the amptitude. so i was just wondering, how i would go about setting up a hps and a mh light togehter, from the sounds of it, it doesnt sound to difficult but i was a chemistry dude, so i was just wondering on ur opinion if it would be possible, how hard it would be, how much probably room is the for accuracy and how important is it, if the wavelengths that got reflected if they would be constuctive or destructive, ect, whoa, sorry for all the questions dude, but if u could lend a hand that would be awesome or anyone else that gets the jist of it
thx guys

well, ok i just tried to log onto the college website & get a presentation explaining the whole fucking lot, but it's shit & i can't so im gonna have to try & explain it on my own.
because the wavelength is so small (nano meters) it makes it extrmely difficult to make it do what you want it to do on a large scale. however in a small scale its easier (they use this superpositioning in CD players & DVD player) its hard on a large scale because; if u had a source of light, the light goes in all directions from that source, meaning that their are thousands & thousands of light waves going away from the source. when one hits a wall (no matter what it's made from) it will reflect back. a grow room would be like the worst place for this because there's loads of different rays bouncing all over the place & depending on how far they've traveled when they meet it can act constructive or destructive. because its such a large space & the waves are so small you have no idea how it will end up. im not clever enough to work that out!
also as the MH & HPS are different light spectrums, they have a different range of wavelengths. blue=MH & HPS=Red
red & blue are on opposite sides of the visible light spectrum, so they have very different wavelengths. from what i know they will not affect each other.

in answer to your question you would have to work out the dimensions of the room to the exact nano meter & work out every possible path the light could travelfrom both sources. in other words unless you were a mega genius it would be fucking hard to do accuratly.

btw don't go taking your light combinations out, cos some will interfere good & some bad & some in between. but in the end it's just like having 2 lights.

anything u dont follow, tell me & i'll try & explain it better, sorry i just got up & im a bit tired.

hey bro, thx for the help, u explained it pretty much how i expected it cause i expected it pretty much to be impossible, and plus my dimensions in the room are off just a lil, the one side is a inch wider than the other side, plus the uneveness of the reflective material and all that. But yea, i think instead of just having a mh and a hps in one room, im just going to exchange my hps ballast for another mh and work from there? because from what ive read is that the both cancel eachother out, correct me if im wrong? but yea what would u think, ive got 2.5 ft wide by 6.5 feet high plus 7 feet long grow space, whats ur opinion bro
and eh thx for the help again
highly appreciated

well this is just my opinion, but if i was in your situation i'd keep the two lights seperate. split it into boxes with one a little smaller & have MH for veg(in the smaller box) & HPS for flower, yes it will prob grow better with MH & HPS at the same time, but fucking hell, it's a weed, it does fine with just HPS in flower. also if you have a veg box & a flower box you can harvest twice as often!!

I haven't had time to read everything here, and re-read to make sure... but I think you people are mixing up on some laws of physics/EM.

Light, does not cancel its self out.

Light waves that combine can double their amplitude or cancel it out, or anywhere in between. All electromagnetic waves are subject to interference. The type of interference depends on wavelength (so MH and HPS should interfere less) and also the alignment of phase. Phase alignment depends on how far the light has traveled (talking nanmeters) which seems completely random. I wouldn't worry about it because the plants are getting tons more light no matter what.

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Originally Posted by smoknjoe

Light waves that combine can double their amplitude or cancel it out, or anywhere in between. All electromagnetic waves are subject to interference.

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I'm not sure, but I think you're wrong.

I think you're refering to the "double slit experiment".

Two EM waves (electromagnetic) can't be added together to create a greater amplitude.

By the same token, they don't "interfere" with each other, and create "interference patterns".

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Originally Posted by turtle420

I think you're refering to the "double slit experiment".

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Yea, I am. The double split experiment proved that the light waves were interfering.

Quote:

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Originally Posted by turtle420

Two EM waves (electromagnetic) can't be added together to create a greater amplitude.

By the same token, they don't "interfere" with each other, and create "interference patterns".

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Type "electromagnetic waves interference" into google.

I hope this can be done peacefully...

Quote:

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Originally Posted by smoknjoe

Yea, I am. The double split experiment proved that the light waves were interfering.

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No. The double slit experiment provides clues for support for both theories... that light/EM "photons" are waves AND/OR particles... are interfering.

Quote:

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Originally Posted by smoknjoe

Type "electromagnetic waves interference" into google.

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I did. I liked the WikiPedia one
http://en.wikipedia.org/wiki/Electromagnetic_radiation

FROM WIKI::: For example, a travelling EM wave incident on a particular arrangement of atoms induces oscillation in the atoms and thus causes them to emit their own EM waves. These emissions interfere with the impinging wave and alter its form.
So... it's probably my fault.

Rephrasing it:
Waves in a vacuum don't interfere with each other.

..........
QUESTION: Where are we going with this?
I don't think that running two bulbs will cause any appreciably interference in the waves/particles of light...

Best to you Joe,

-turtle420 :cool:
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