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OK now I'm really confused ! ~ MH lighting @ end of flowering Sativa's ?

Owl Mirror

Owl Mirror

Active member
Veteran
Well folks, the more I read the more I learn.
I'm new to growing but, I've read a fair bit before getting started.
While I have some short-season Indica's to keep me supplied for my medicinal needs, I have decided to use some of my grow room to grow out some pure Sativa strains. I have been seeking out information regarding how best to grow these long-flowering Sativa's indoors.
This morning I came upon a thread (MrNice) which says that those who grow Sativa indoors, switch their lighting from HPS to MH in the last few weeks of flowering to encourage the most potency out of the Sativa's.

I had always read that MH was best for vegging and, the HPS was used primarily for flowering. How would switching from HPS to MH effect the flowering plants?
I have two lights in the same space so, would it be beneficial to change one light over to MH and leave the other as a HPS ?
How would this action effect any Indica plants in the same room?

Seems the more I learn about growing this plant, the more I get confused !
 
D

danny karey

When I grow with a MH, my buds get tighter and harder, didn't notice more potent, maybe thats the reason too........To help the yeild on those Wispy sats.

Wish ya the best, and good luck growing those sats, they can be very very good.

Danny
 
Hazy Lady

Hazy Lady

Prom Night Dumpster Baby
ICMag Donor
Veteran
Hi Buddy, I read that same thread, you know I grow mostly Sativa x's and so have an interest as yourself, I sometimes have to grow (veg) plants under my HPS and they never get to full health, never shine or grow as fast as under MH, or CFL's for that matter, but once I flip those plants, now in flower, with the correct spectrum for flowering, absolutely shine!, by week 3 or 4 they never looked better, conversely whenever I used MH to flower I did get tighter buds as danny did, but I believe it was extra leaf, not calyx, It was such an ideal spectrum for veg growth the plant could not help itself!, I also had more instances of bud rot under MH and I put that down to extra leaf/moisture. Our MH died years ago and we never replaced it, I have no intention of ever getting one especially since the 125W and 250W flouro's came out.
 
Owl Mirror

Owl Mirror

Active member
Veteran
Hazy Lady said:
Hi Buddy, I read that same thread, you know I grow mostly Sativa x's and so have an interest as yourself, I sometimes have to grow (veg) plants under my HPS and they never get to full health, never shine or grow as fast as under MH, or CFL's for that matter, but once I flip those plants, now in flower, with the correct spectrum for flowering, absolutely shine!, by week 3 or 4 they never looked better, conversely whenever I used MH to flower I did get tighter buds as danny did, but I believe it was extra leaf, not calyx, It was such an ideal spectrum for veg growth the plant could not help itself!, I also had more instances of bud rot under MH and I put that down to extra leaf/moisture. Our MH died years ago and we never replaced it, I have no intention of ever getting one especially since the 125W and 250W flouro's came out.
Click to expand...

Thanks HL, so in your opinion it does serve to increase leaf growth, even under a flower schedule ? OK
I've already grown a mostly leafy bud plant, not interested in repeating ;>}
 
Owl Mirror

Owl Mirror

Active member
Veteran
danny karey said:
When I grow with a MH, my buds get tighter and harder, didn't notice more potent, maybe thats the reason too........To help the yeild on those Wispy sats.

Wish ya the best, and good luck growing those sats, they can be very very good.

Danny
Click to expand...

Thanks Danny, yes this should be an interesting project.
I just don't want to screw it up after investing all that time and energy.
I wonder why it is nobody has designed a light which emits the same waves as does our sun.
I suppose we could do without the x-rays but, who knows,
maybe this plant needs this wave or ray to grow best?


Cold Fusion, in a tube ?
Wouldn't that be exciting? Creating a miniture sun inside a bulb.
 
Owl Mirror

Owl Mirror

Active member
Veteran
*mistress* said:
sunmaster warm deluxe and neutral deluxe supply far more uv light than hps alone. density, texture and aromatics diiferent w/ mh included thru-out season.

this may be helpful, amnong others here on icmag:
https://www.icmag.com/ic/showthread.php?t=132224
mh lighting for entire grow?

enjoy your garden!
Click to expand...

Hello mistress, I have two 400 watt lights inside a 6L x2.5D closet. Are you saying I would benefit by having one MH and one sunmaster warm deluxe or neutral deluxe ?
Does this hold true for both Indica as well as Sativa?
Would one strain be better off growing under the MH, while the other fair better under the HPS side?
 
MarquisBlack

MarquisBlack

St. Elsewhere
Veteran
They say that a 1:2, Metal Halide:HPS spectrum emulates our sun the best. For example, in my flower room I have two 1000w HPSs on either side of the room, with a 1000w Metal Halide in the center.

However, if I were growing pure Sativas, I would have two MHs on either side, with an HPS in the middle.

Equatorial Sativas prefer Metal Halide because they best emulate the spectrum that the plant would experience in its natural environment. North/South of the equator, a good fraction of the "day" the sun is shining at an angle through our atmosphere, causing an orange-ish HPS spectrum. At the equator, the Sun travels in a more straight overhead fashion, less affected by the natural tilt of our Earth. Because of this, not only does the equator not experience as "orange" a Sun as the one the rest of us are used to, but less UV rays are filtered by the atmosphere, because the photons have to travel a shorter distance through our atmosphere.

The UV light levels are key here, IMHO.

Edit: Also, more MH for Indicas during flower isn't necessarily detrimental. Mixed spectrum will almost always beat HPS Orange, if not in weight, at least in quality.
 
Owl Mirror

Owl Mirror

Active member
Veteran
MarquisBlack said:
They say that a 1:2, Metal Halide:HPS spectrum emulates our sun the best. For example, in my flower room I have two 1000w HPSs on either side of the room, with a 1000w Metal Halide in the center.

However, if I were growing pure Sativas, I would have two MHs on either side, with an HPS in the middle.

Equatorial Sativas prefer Metal Halide because they best emulate the spectrum that the plant would experience in its natural environment. North/South of the equator, a good fraction of the "day" the sun is shining at an angle through our atmosphere, causing an orange-ish HPS spectrum. At the equator, the Sun travels in a more straight overhead fashion, less affected by the natural tilt of our Earth. Because of this, not only does the equator not experience as "orange" a Sun as the one the rest of us are used to, but less UV rays are filtered by the atmosphere, because the photons have to travel a shorter distance through our atmosphere.

The UV light levels are key here, IMHO.

Edit: Also, more MH for Indicas during flower isn't necessarily detrimental. Mixed spectrum will almost always beat HPS Orange, if not in weight, at least in quality.
Click to expand...

Thank you for that explanation, now it's more clear to me as to why & when you might use these during flowering.
 
M

*mistress*

Member
Veteran
Owl Mirror said:
Hello mistress, I have two 400 watt lights inside a 6L x2.5D closet. Are you saying I would benefit by having one MH and one sunmaster warm deluxe or neutral deluxe ?
Does this hold true for both Indica as well as Sativa?
Would one strain be better off growing under the MH, while the other fair better under the HPS side?
Click to expand...
1 sm warm deluxe (though neutras deluxe is >coins w/ similar spaectral output) + 1 hps. eye conversion very good, if have mh ballast.

in imagination, use purple + red party lights + uvb bulbs + daylight floros. the intensity of the bulb is not a factor here; just spectral diversity. attempt to mimic aurora borealis + dusk, etc. different party-light colors for different stages of maturity.

if had to select only 1 bulb, would be sm warm deluxe. every gardener will find their own particulars. that bulb produces balanced fruit, in fictitious garden. but, generic mh & generic hps have worked well too. plant does not care brand of bulb, only kelvin temp/par watt/etc of the light.

this may be helpful, as well:
https://www.icmag.com/ic/showthread.php?t=108993
lighting conversion data

&

https://www.icmag.com/ic/showthread.php?t=127379
this is a goldmine of ... laboratory research

enjoy your garden!
 
N

NOYB

From what I understand it's a very bad idea to switch from HPS to MH for the last few weeks of flower for any strain. Sat doms (but especially pure sats) will do better, or at least will express more of their potential, if you use bulbs with more blue spectrum. I use warm halides for flower for everything but would not hesitate to go with cools for sats/sat doms. I have flowered with cool halides before and simply awesome quality.
 
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