resin production and metal halides

ok.. while doing some research i came across an interesting article..

Ed Rosenthal (14 Jan, 2005)
Can I switch to metal halide during the last few weeks of bloom?
For years I've been growing under high pressure sodium (HPS) lights for both the grow and bloom phases, because HPS lamps emit more useable light per watt. This results in a better yield.

However, UV light stimulates resin production and metal halides (MH) emit more UVB light than HPS lamps. The bud has pretty much stopped growing by then so the reduced light output of the MH would not affect yields too much. Does it make sense to use MH lamps during the last few weeks of the bloom to stimulate more trichome/THC production?

Or is there a better way to add UV light to the end of the bloom phase?

Budleigh,
Charlottesville, Virginia


Potency increases with more UVB light, so it would be a good idea to increase the amount of UVB they are receiving.

I like your idea of replacing the HPS lamps with MH during the last one to two weeks of flowering. Your reasoning – that flowering growth has slowed so that MH lamps, which emit considerably more UVB light than HPS lamps, would increase the quality – could work. It's worth a try.

You can also supplement UVB light with a reptile type light found at most pet stores.

may try that this harvest myself with a couple..... i usually stick my inside flower outside if it is around that time of year because the outdoor is ALWAYS stronger. but i only leave the m out for about 6-8 hours of their 12/12 cycle.

i use a dual-spectrum light (600w HPS/ 400w MH ) through the whole grow... don't know if it matters or not but i like the results...

Dudes. There is a crazy new bulb on the market that is meant for the last week or even two weeks of flower. It emits an insane amount of UVA light to the plants (10,000k). i just bought it after my local grow store guy was raving about the amazing things it has done to his plants. It's only made by 1 company right now. I can link what i have to show you; their light chart (scroll all the way to the bottom, its the 10 kelvin one on their product list). You may be able to buy a bulb from them, but probably not. There are a few stores that sell them now(but only one store in 100 miles of me), and people say how amazing they are. Has a pink/purple flashing glow, bulb is insane looking.

Guy at store told me that it makes the resin and crystals multiply by 10. Im about to experiment with it in the next few days.

The bulb is made by LifeTech - http://www.lifelighttec.com/f/LLI_Fall07RetailPricingWeb_B1.pdf

you sure its UVA? cuz from what i heard....UVA will kill your plants.


UVB is what you need!!!

a jon,MH bulbs do work alot better for resin production,way better!Plants dont stop growing the last two week its the opposet,they grow the MOST during the last two weeks.Its best to add a MH or a uv bulb.Loudblunts if uva killed plants we wouldnt have any the sun puts out alot of uva rays.Yota how much did you pay for that bulb?Its just a ceramic metal halide bulb i believe,they've been out for a year or so now.Yes the 10k is suppose to be AWESOME for the last couple of weeks of flower.I usally use a hortilux blub,it has 30 percent more blue light and way more lumens than the standered bulb,its always work VERY well,i believe i need a new bulb so i swiched out the hortilux for a reg MH(the last two weeks of flowering)it worked awesome the crytals are better then usally.The next bulb i buy is going to be the Reto-fit ceramic MH bulb,it works in stander hps fixture.Ps it wont work with the digital ballast only the coil ballast.Hes a link>>> Phlips MasterColor Ceramic Metal Halide ~ CMH ~ HPS-Retro White Stay Safe!!

ronbud - the bulb was about $115 bucks.

loudblunts - I'm sure it is UVA, it says so on their light chart as well. And yes, that much UVA does kill your plants. That's what it is supposed to do. Stress and basically kill your plants while increasing resin and crystals, and colors. Thats why you only use the last week, or possibly 2 at most. Im told your plants will do some funky shit during this time. Ill see this week

ronbud, why is it that they call them ceramic metal halide, when they can be HPS also?

thanks for confirming yota....


could ya keep me posted on your progress? perhaps a pm?

ya, im putting in the bulb tonight, but the real test is gonna be next grow. I think its a little late this time, but well see if it does anything

yota i dont believe its uva you want,i belive it uvb,but we will see.Good Luck & Stay safe!PS keep us posted.Did you check out that link i posted,$50.00us for a 400watt not bad.The 600 should be coming out soon.

ya i checked it out. I have a 600w one. I know its more common to hear UVB, but according to this site, they use UVA. So the bulb was introduced last night and ill keep you posted over the next week. i didnt really understand your link, do they sell UV bulbs?

No these are not sold as grow bulbs,there made for companies that have alot of hps lighting(overhead lighting).They are being used because the light is much brighter and clearer.For more info ckeck out the thred in grow room desighs & set ups,its called That One Dude.Im sure you will be sorry you spent that much on that bulb even if it has LOTS of uvb rays.Good Luck & Stay Safe!!Ps THE FURTURE IS CMH LIGHTING.

i found out today that the bulbs have UVA and UVB in them. Even there HPS and MH bulbs have some small amounts of UVA and UVB. Thats what makes their bulbs different.

intresting bro let us know how it goes

Pate (1994) talks about uvb in his paper the chemical ecology of cannabis. the uvb is photoactive and responsible for changing precursors into thc......

ive seen a few people using the cmh bulbs and ive yet to see where the benifits overrun the price of the bulb.
if you are having resin production problems why not spend that $100+ that people buy cmh bulbs with on some better genes to make the resin that you are looking for?
until someone shows me different with results, im going to stand by the tried and true methods

A Full Spectrum MH and some Purple max and Gravity will produce big, rock hard, sticky flypaper buds, guaranteed. Hydro store employees(especially owners) are just as deceiving and grimey as dealers, seed breeders and used car salesman. They will tell you anything to get that $. Why anyone would be discussing growing marijuana with a civilian in a store is beyond me, unless they are your friend and even then it's not practical.. Be careful guys, I have gotten my freedom taken from me thinking I could trust people.
... Snuff

kochab said:

ive seen a few people using the cmh bulbs and ive yet to see where the benifits overrun the price of the bulb.
if you are having resin production problems why not spend that $100+ that people buy cmh bulbs with on some better genes to make the resin that you are looking for?
until someone shows me different with results, im going to stand by the tried and true methods

Click to expand...

I don't have Gene or resin production problems. But can you argue if you were to triple the amount of crystals on your bud. Tried and true methods are great, but u cant ignore new technology. (well u can if you want i guess, im choosing not to)