Indoor Hps Bulbs or MH bulbs for autoflowering ?

[dannyb131]

Hello, I was wondering when growing an auto flowering plant should you still use a MH bulb for the first bit until it starts to flower then switch to an hps ?

Thanks

 

[hereb4]

yes ,the use of MH for veg is recommended by some. others use Hps all the way through....and another theory has you using MH for veg....HPS for flower..then switch back to MH for the last week or 2 of flowering.

 

[Carl Poot]

most use either mh for veg and hps for flower. Or hps all the way through. With way is perfectly fine.

 

[Peekineeze]

another theory has you using MH for veg....HPS for flower..then switch back to MH for the last week or 2 of flowering.

Any idea what the logic is behind this? Why switch back to MH?

 

[Muddy]

If you already have both, then I would use the MH for veg and switch to the HPS around week 5. HPS will work well the whole grow, especially if the HPS bulb has an expanded blue spectrum.

 

[hereb4]

Any idea what the logic is behind this? Why switch back to MH?

the theory is that trichomes act as a protective layer....the switch back to MH at the end may stimulate the plants need for more protection...thus more sticky..
I tried 1 grow that way...but,switched to t5 now,so I have no comparative results to either prove or disprove the theory....but,I think it worked well enough to recommend others to try.

 

[midman4u]

i use both throughout complete grow!

 

[yodabuds]

Do you have two lights with one bulb
Of each in? Or do you switch back and forth during the grow? I got a led and mh running in same tent right now, will switch from mh to hps in a couple of weeks when my ladies get underway flowering....
Yoda

 

[MrEastside]

High pressure sodium lamps produce mostly the yellow light and this lamp light spectrum is mostly at the end of visible light frequency. Because of this altered spectrum HPS lights are better at the flowering stages of the plants life than the seedling phase. At the start of cannabis life it needs more blue spectrum light so it could develop healthy leaves, stems and roots. But when cannabis starts flowering as the Sun turn yellowish red when the summer comes to end and the sun is lower at the horizon. When sun is not in the middle of the sky itneeds to travel through more dust and other particles that refract and reflect the light so the spectrum is altered and it become more Red and yellow! This red color spectrum is beneficial to plants because the small photosynthetic pigments that absorb red light have a bigger influence on flowering than the overall growth. If an autoflower plant would be grown from seed under HPS lamp it can get stretched and sturdy as it won’t have enough blue light. Because the photosynthetic pigments that absorb blue light send more energy to stems and leaf, more blue light rather than the red spectrum light is needed for the seedling and vegetative growth stages and because of this growers who usually use HPS lights tend to
start plants under MH lamps or fluorescent tubes that can radiate the blue light.