MH for Flowering?

I am just wondering if anyone has ever tried this or knows something about it. So the question is: Can you use an MH grow light for flowering? Say for example a 400w MH. Just looking for input

can you? yes. Should you? HPS is better for flowering.

you can use Miracl Gro and CFL's to grow cannabis..wont amount to much be you can do anything if you put your mind to it.

if u do. you will get better rusults with a 2.1 ratio of hps and mh. you can swap them round for veg 2 mh and one hps.

You can, but the you won't get the same yields you would with HPS. The buds will also be fluffier, but may have a bit more resin due to the UVB the MH has and HPS doesn't have. Really the best option is MH + HPS. It is kind of silly to buy a MH setup though, since you can run MH or HPS off a HPS ballast, but not the other way around. Typically HPS ballasts are like $10 more than MH.

nubbis1020 said:

I am just wondering if anyone has ever tried this or knows something about it. So the question is: Can you use an MH grow light for flowering? Say for example a 400w MH. Just looking for input

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Just asking if a MH can be used is a broad question. One of course can be, but your results will vary depending on the Kelvin rating of the MH bulb you use.

An HPS will normally be around 2000K or 2100K, a vegging MH would be 6500K ... but there are 2000K MH and 3200K MH etc. and the closer you can get to that HPS 2000K or 2100K the better your results will be using a MH for flowering. If you attempt to use something like a 6500K or anything half close, well, that will be a horse of a different color when it comes to what your results end up being.

Brick Top said:

Just asking if a MH can be used is a broad question. One of course can be, but your results will vary depending on the Kelvin rating of the MH bulb you use.

An HPS will normally be around 2000K or 2100K, a vegging MH would be 6500K ... but there are 2000K MH and 3200K MH etc. and the closer you can get to that HPS 2000K or 2100K the better your results will be using a MH for flowering. If you attempt to use something like a 6500K or anything half close, well, that will be a horse of a different color when it comes to what your results end up being.

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You can get a 3000k MH lamp here: http://www.plantlightinghydroponics.com/solarmax-gold-400w-3000k-metal-halide-grow-bulb-p-2363.html

It's over $60 for just the lamp though, also the lumen output on a 400w MH vs a 400w HPS is about 20,000 lumens less for the MH.

I have run my 400w MH for this whole crops light cycle. Veg and Flower. They look good..they smell great and they have fat buds that are no smaller at all then what I get when I use my HPS...

I do notice they are stickier...it all started because my HPS gets too hot and I didn't have adequate ventilation to keep the light cool...but my MH was just cool enough to get by...so I decided to use just the MH...then I got cold feet and thought I should give them a little HPS...like for that day....cut the light off, let it cool, screwed in the HPS and it came on got brighter and brighter and brighter and like blinding and then it got darker and darker and darker til just the little middle part was like glowing red after I unplugged the thing...so I figure there is my sign that I don't need an HPS and I should keep on with the MH...everything looks just like it should for where it is...

can be used but hps better or a cmh better as well

oooohhhh...I have a new CMH on the way. Hooray! I just really don't like HPS...gross orange light.

Ahh its a MAN BEAR PIG..

Or a BEAR PIG MAN !

missnu said:

I have run my 400w MH for this whole crops light cycle. Veg and Flower. They look good..they smell great and they have fat buds that are no smaller at all then what I get when I use my HPS...

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Pics or it didn't happen.

switched lights to 12/12 5 weeks ago in this pic. Nothing but 400w MH whole time.

So there. Ha

missnu said:

So there. Ha

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So I see there that you haven't finished a full cycle yet to compare. I'd be interested in seeing harvest pics of mh compared to the same strain under hps at harvest. Also a final weight of each. Your buds look good at 5 weeks, but still a ways to go. Personally I really wanna do a mixed spectrum with hid lighting, but don't have any more space to add mh. I put some cool CFL's below the canopy to add a little blue.

missnu said:

oooohhhh...I have a new CMH on the way. Hooray! I just really don't like HPS...gross orange light.

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"Gross orange light" or not, a HPS puts out more of the light spectrum that plants use in flower than a CMH, which is a full spectrum bulb that is always putting out at least some amount of light spectrum that plants either do not use or do not always need.

So how is an HPS better? I mean that chart compares CMH and HPS and the CMH looks a lot better to me especially since I already know an HPS is not needed in anyway, a MH with more colors sounds to be just the bees knees.

I like gross orange myself.

missnu said:

So how is an HPS better? I mean that chart compares CMH and HPS and the CMH looks a lot better to me especially since I already know an HPS is not needed in anyway, a MH with more colors sounds to be just the bees knees.

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It [the CMH] is wasting energy on producing a spectrum of color that isn't used by the plants...

I think...