MH + HPS or not?

stvitusdance

stvitusdance

Well-Known Member
HI!

I have two 400 watt HID lights. I'm wondering what people think about having a HPS in one and MH in the other throughout the grow cycle? Or is it better to stick with the standard MH thru veg and HPS in flower in both reflectors? thanks!
 
<stealthgrowing>

<stealthgrowing>

Active Member
sogbunn said:
i second that!!!
Click to expand...

Well I won't be so quick to agree... If you combine both lights then you will be using 800 watts of growing power. you can also add the lumens of the 400 watt HPS to the lumens of the 400 watt MH. You will almost double the lumens of one light. I say almost, because I think the MH puts out slightly less lumens than the HPS. So doubling up on the light, should actually give you better growth potential, because of the combined lumens. Its a matter of how you arrange the lights that bears importance here... I would arrange them in such a way that they both shine roughly in the same spot and rotate the plant on a daily basis. The only issue is power consumption and heat generated in the grow room. You would have to cool two lights vs. just one, so a duct system is in order with a fan attached I would think.
 
lisa99

lisa99

Active Member
Ive played around with this and found that when I added the blue spectrum (MH) throughout the light cycle, my nugs were a bit stretched. I certainly didnt find it to be beneficial, just stick with the red spectrum (HPS) for nice tight, dense buds. Oh and by the way - be mindful of what ballasts you have first. Your post says you have 2 HID lights, never put a MH bulb into a HPS Ballast. They look similar, so just a heads up.
 
stvitusdance

stvitusdance

Well-Known Member
thanks everybody for your response. i'm not worried at all about power consumption or heat. this is a small grow space. both hoods are enclosed and vented. my space is roughly 5' long x 6' tall x 2' wide.


<stealthgrowing> said:
Well I won't be so quick to agree... If you combine both lights then you will be using 800 watts of growing power. you can also add the lumens of the 400 watt HPS to the lumens of the 400 watt MH. You will almost double the lumens of one light. I say almost, because I think the MH puts out slightly less lumens than the HPS. So doubling up on the light, should actually give you better growth potential, because of the combined lumens. Its a matter of how you arrange the lights that bears importance here... I would arrange them in such a way that they both shine roughly in the same spot and rotate the plant on a daily basis. The only issue is power consumption and heat generated in the grow room. You would have to cool two lights vs. just one, so a duct system is in order with a fan attached I would think.
Click to expand...
 
stvitusdance

stvitusdance

Well-Known Member
thank you! i have 2 digital ballasts. one i got from from HTG supply about 3 years ago that says on the chassis "MH or HPS" but came with a HPS bulb and a MH conversion bulb. the other digital ballast came from HID HUT with a HPS bulb and they said don't use a converstion MH bulb. all very confusing.
 
Steadmanclan

Steadmanclan

Well-Known Member
use all hps for bloom right up untill the very last 10-14 days before harvest. adding the blue spectrum has been proven to help in stimulating resin production during the final ripening phase. they actually make a hid bulb that is 10,000kelvin. as opposed to the normal 6500k of a metal halide.

as has been said, using your mh during the majority of your bloom cycle will produce airy buds.
 
Steadmanclan

Steadmanclan

Well-Known Member
yes...
two hps bulbs right up until the end when you switch one out for the white light...
you won't be unhappy with the results..
 
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