Can I use my MH lamps successfully from start to finish? Will the crop be worth the smoke? Why is the HPS lamp better?

Metal halide (MH) lamps can be used for flowering, but there are two problems that they have when compared with high-pressure sodium (HPS) lamps. The first is that they don't emit as much total light. HPS lamps emit more than 20% more light, so MH lamps are not as intense when covering the same area. Second, they do not emit as much orange and red light as HPS lamps. These spectrums seem to promote flowering. However, MH lamps do have several advantages over HPS. First, they are less expensive to purchase. Second, the light does not have a really weird telltale spectrum. It looks white, not pink or amber. Third, the lamps emit more UVB light than HPS lamps, although still in very small amounts. The amount of UVB light plants receive is directly related to the quality of the buds. The more UVB, the higher the quality. Buds grown under MH light will not be as big as buds grown using HPS lighting. However their quality will be as good or better.

Thanks for posting that up 4Ever. I was reading that on CannabisCulture just the other day. I believe it came from Ed Rosenthal?

"Copy and Paste" works, but always try to give the original author the credit for writing it...don't want folks thinking we are stealing their work!

Good points though...I think a lot of growers have MH in their flower rooms along with the HPS. I've got 1200W of HPS now, and am going to add in a 400W MH to fit between the 2 HPS fixtures. Should create a great spectrum for flowering.

ISO

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it was a document i downloaded no author was on it.but thanks ed!1200w of hps thats serious power man your right that mh will give your lighting a overall good spectrum for your plant growth on all levels there.

Yep..it'll help. Thaty 1200W (2 X 600W in 2 fixtures) is hanging over a space only 7' X 4', so adding another 400W of the MH will give me 1600W total. Better yet is that they're in air-cooled fixtures so I can keep them all cool..

ISO

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sounds good cant wait to see the beauties that come from that configuration of lighting.i myself have used hps and flouro and if you ask me i think when i did use the two in conjuction with each other i did get more heartier buds than just using the hps alone.so hps and mh got to be better you sould have a gigantic havest.

My 1K HPS burnt out, a while back. I have a MH conversion bulb in the fixture, now. I have harvested a couple of crops, using the MH. I have seen no difference in the bud size or density. The MH seems to run cooler, too. I start flowering under a 400W HPS at one end of the room. Then, I move them under the 1K as I harvest a few from under the 1K. It's a 2 week cycle for harvesting. I am going to add another 400w HPS next to the 1K, soon.

Pappy

what about the trichome production do you see a differance there? is there more or less?

I haven't really noticed any difference.

Pappy

from what I have known MH produce denser, tightly packed buds (Which ended up weighing more than the overall weight of the HPS bud). There are several advantages as well as disadvantages. MH will need more attention(light placement) due to heat; While an advantage of MH over HPS is how it puts out such tightly spaced nodes. Id say its just a matter of preference. Most commercial growers go HPS, while the personal growers, connesiuers tend to go towards MH...shoot, some even mix with fantastic results. Metal Halides can also come specifically for flowering or veg(Red or blue).