Can I use 400W 20000K MH bulb

[ulis5714]

Can a 400Watt, 20000Kelvin Metal Halide bulb be used for growing cannabis? I can buy this bulb for $20.00. It has a life of 10000 hours. But, I have not been able to find the spectrum yet. I will call the company tomorrow. Can anyone offer advice on this Kelvin rating before I buy this bulb? Edited February 12, 2012 by ulis5714

[louise]

20,000K MH is an aquarium light designed to be used in a salt water tank. They are good for simulating deep water and raising sea dwelling invertabrates... not what you want for growing cannabis. 5000K to 7000K is more appropriate for growing plants on dry ground. Edited February 12, 2012 by lou lou

[ulis5714]

OK! The reason why I asked about this spectrum of light is because I read (Cannaversity, I think) that 14000K-20000K was good to veg because of the deep blue spectrum. I have not grown anything as of yet, I am trying to get educated. My plan was to germ with LED, veg for 1 month with 4000K MH, flower with 2000K HPS, and then the last month or so use the 20000K MH to finish. The deep blue spectrum is supposed to enhance THC. Will my plan work? Look at Cannaversity, Lighting & Electrical, What MH spectrum is best for vegging? Edited February 12, 2012 by ulis5714

[louise]

The only time I have seen 14000K used was to maintain mothers... I use HPS (philips son-T-agro) in flower so I have no idea if your planned spectral changes will make much difference to the final product.

 

Personally, if this is your first grow, I think you would be better off simplifying things until you have some practical knowledge of the way cannabis plants grow and flower.

[ulis5714]

I plan to use the cheap bulbs. Other posts I have seen on different sites say the expensive bulbs do no better than the cheap ones. The LED bulbs were $7.50 each, 12 MH 4000K were $108.00, 10 Plantmax 360W conversion bulbs were $170.00, and 10 20000K MH bulbs will cost $208.00. I have some bagseed to test this growing technique with. Did you check out the article on Cannaversity? What did you think of it?

[louise]

Like I said... I haven't experience of using lamps that far to the blue end of the spectrum. Oz wrote the article and I expect he has more knowledge of MH than I do.

[ulis5714]

OK! It is not that I don't like talking to you, lou lou, but could you put me in contact with Oz? THANK YOU VERY MUCH! I have just now sent an email to Oz. Thanks again! Edited February 13, 2012 by ulis5714

[MongyMan]

OK! The reason why I asked about this spectrum of light is because I read (Cannaversity, I think) that 14000K-20000K was good to veg because of the deep blue spectrum.

 

Have you got a link to what you were reading ulis5714?

 

Peace MongyMan

[ulis5714]

Hey, MongyMan! I got it from Cannaversity.com. I am not very computer literate, and I am new to the tools of this site. If you went to Cannaversity.com,Cannabis Cultivation, Lighting & Electrical, What Metal Halide Spectrum is Best For Vegging?, you should be able to find it. If not, I will do my best to help. Also, on another site, I found a thread that said: Ed Rosenthal's Marijuana Growers Handbook states that "the amount of UVB light a plant receives affects THC and terpene production. Plants grown under higher UV levels are more potent." I do not know if any of this is true. I came on this site to ask the experts. I hope that together, we can research this theory, and come to useful conclusions. Also, greenmanspage.com, marijuana THC, has a somewhat lengthy article that includes evidence of effects of UVB on THC. Stuff like this is very interesting to me. The thing is, how much UVB can a plant take before it gets overloaded and dies? Yes, in my research on growing with more MH spectrum, I realize that all that UVB radiation may stunt the plant's growth. But, I am not interested at this time in growing the biggest, only the best. Edited February 13, 2012 by ulis5714

[Vape]

Hi ulis5714,

 

As a relative newbie to growing, i can only suggest you keep it as simple as you can for your first grow, cause there will enough simple things that can go wrong,

 

so i can only suggest you read lots and take notes , collate the material and make your own educated judgement, have a go and see what happens. after all its just a plant ,

 

we arent putting monkeys in space, and this aint NASA.. the K.I.S.S method is the way for any newbie. Trust Me.!!

 

cannabis needs water food and light, find out what kind cannabis likes and go from there, good luck with your new found hobbie!..all the best.

 

sirvapealot..