Metal Halides in flowering... a better high?

[big mike]

So, what about the idea of a dual bulb hood and using both spectrums? Get the yield of the HPS with the potentcy of the MH?

thats what im hoping for, i got the growzilla:
http://www.planetnatural.com/site/image.html?sku=growzilla-reflector

Ive had a 400hps all by itself for a while and just recently added the 400 mh..

doubleing the light wattage should do something for the buds, but will a 400hps/400mh be that different than dual 400hps.....

 

[simba]

the closer to CRI of 100 the better..

i say use MH and HPS.. you will get better PUR>>>>

also the MH dumps the UV that creates more reason..


also it mimics the real light..

spring.. Blueish-red,,, summer RED with lil blue..... Fall BLUE-red...

in short if you run MH and HPS you will see a great difference...

 

[Nostromo]

I am not that sure about trying both, MH and HPS; we don´t even know if this hypothetical better high that some very experienced members talk about derives from the presence of UV, the MH or from the absence of the HPS. Personally, I think that nifty's proyect is incredibly interesting, but the one Nite Tiger proposed (8 months) will help the most on the thread's subject. It is more simple and, if any other members can do equally, then we can discuss if the UV is the reason for the difference. Just my 2 cents.

 

[HeadyPete]

Hey Nifty, once again, that is very cool that you are doing this. I am very interested in your experiment and this thread (or your own) is subscribed!

 

[HeadyPete]

Nostromo, some say it helps reduce stretch in flower if you use MH for the first two weeks after switching to 12/12, then use the HPS for the remainder. Not sure if this would affect yield but could help tame some gnarly sativas...

 

[Truth]

well you always could supplement HPS with a few UV lights.

 

[Truth]

Nostromo, some say it helps reduce stretch in flower if you use MH for the first two weeks after switching to 12/12, then use the HPS for the remainder. Not sure if this would affect yield but could help tame some gnarly sativas...

Yes it is true that MH during first 2 weeks keeps down stretch. And as a boost, give veg nutes for the first week or two if you like, since the increased ratio of P and K cause stretch. It won't affect yield in a bad way...you may very well yield more this way. Your nodes will be closer, plants shorter, which means more light to the lower portions of the plant. Buds will connect easier and form into thick dense nuggets, not airy ones. It depends on framework to create large dense nugs..if your nodes are spaced too far, they will stretch upwards, and not sideways.

 

[Nostromo]

Hi, HeadyPete. I know that, but the point is if going MH on the whole process affects the high for the better. Read the first Verite's post on this thread. It is very interesting. He states that he hasn't use any HPS for ten years and he doesn´t miss them a bit.

 

[Guest]

Hey you werent the one running the 'cool deluxe' bulb test grow thread were you?

Nope...my first and only account started in November '06. Best case scenario...I think...is use cool halides for the stretch in flower, HPS for the bulk of the flower cycle and halides for the last two weeks. I've never tried it but seems like that might be the ticket. I've seen converstations about MH vs HPS as long as I've been online and nothing definitive for me yet. Seems like some of what one grower sees contradicts another's experience. If I had to pick one bulb to work with through flower I'd say a warm halide. Right now I'm 100% HPS start to finish because...that's the way it works sometimes in life.

 

[pray4pistils]

What about lighting "stages"?

What about lighting "stages"?

If I had to pick one bulb to work with through flower I'd say a warm halide.

In my flowering area I've got 1x 400W MH which I use for the first 3-4 weeks and then 1x 400W HPS for the next 3 - 4 weeks. My particular grow environment (and equipment availability) made this the obvious solution at first. But, do y'all figure that this set up could also make sense from a scientific point of view?

Sure, the full spectrum benefits are there if both light types are used at the same time on the same plants. I'd like to know, though, if there is any strategic advantage during the first and second halves of a flowering period. Perhaps doing it my way just keeps the plants bushy during the stretch-prone first few weeks and then lets'm puff up in the end. Or, maybe that this method closer emulates nature's seasonal effects reaps benefits?

Yeah, any clarification on this will be interesting to know.

 

[Guest]

Metal Halides contain more UV light which may very well increase potency. I use a 250W HPS with a supplemental 25W UVCFL. I've grown the same strains both with and without the UVCFL, and the potency increase is noticable with the UVCFL.

 

[BCGrown]

Hey Sweet, sorry just to clarify...
I've noticed MH produces larger buds, not more dense. HPS produces smaller but much stickier and a little more dense, hence the reason I've never really noticed a yield difference.
This could all be due to strain though, I'm not an expert, just what I've noticed.
Make sense?

 

[- ezra -]

Verite - great info there man. I found that an interesting read, particularly the part about the alternate biogenic pathways.

"However, studies by Brenneisen (1984) have shown only a minor difference in UV-B absorption between THC and CBD, and the absorptive properties of CBC proved considerably greater than either. Perhaps the relationship between the cannabinoids and UV-B is not so direct as first supposed."

the relationship betreen UVb and THC biosynthesis seems for from clear. To me it appears unlikely that the relationship is as simple as UVb absorbtion properties of THC leading to higher THC levels. I definately agree that natural sunlight is capable of producing buds with a superior canabinoid profile than indoor grown herb. I just dont think its as simple as what you suggested, but I would say yes there is a link to UVb on some level.

Nifty - Nice MV tanning lamp! I am sure that thing will put out plenty of UV for your experiment. Looking forward to your results.

- Ez

 

[HeadyPete]

I hear you, Nostromo. What if you ran both together? Wouldn't you get the best of both worlds?

My plan is to veg and flower 4 plants 1st 2 weeks under MH ( Sunmaster neutral 400w), then add 400W eye/hort HPS for rest of flower. Note that i am also building a motorized turntable to slowly rotate the plants throughout the day cycle for even light distribution. I am interested to see how it works out.

I am also keen to see how the other experiments work out. It's so great we can all do this and report back.

 

[Verite]

Sooner or later when Im inbetween breeding projects I hope to run a cool deluxe test on a familiar strain. I have run other tests with other high uv-b outputs [ like adding a 175w mercury vapor to standard MH ] but stopped them after they had a side effect of turning the leaves super dark green on the verge of black.

The problem with reptile lights and tanning booth bulbs is the lack of decent penetration coupled with major intensity lost after a short time of usage. Much moreso than any MH bulb. Even the bulb Nifty listed loses 90% intensity after 28 inches, whats worse is that bulb loses 30% intensity after running only 90 hours [ 7.5 days of 12/12 ]

So unless your doing a small sog test and replacing the bulb every two weeks to keep up levels of UV Im not sure on how much difference thats going to be compared to running an enhanced MH hid. A decent 1000w hid will throw good intense light [ UV and all ] around four feet or more.

Since Im fond of Sunmaster bulbs I thought I would post their listed spectrum charts and specs.

Warm Deluxe

Neutral Deluxe

Cool Deluxe

Here by comparison is their Super HO HPS bulb

Heres the lumen/PAR specs etc

 

[Verite]

They also had a decent explanation of PAR.

PAR Watts for Plants

Watts is an objective measure of energy being used or emitted by a lamp each second. Energy itself is measured in joules, and 1 joule per second is called a watt. A 100 watt incandescent bulb uses up 100 joules of electrical energy every second. How much light energy is it generating? About 6 joules per second or 6 watts, but the efficiency of the lamp is only 6%, a rather dismal number. The rest of the energy is dissipated mainly as heat. Modern discharge lamps like high pressure sodium (HPS) and metal halide convert (typically) 30% to 40% of the electrical energy into light. They are significantly more efficient than incandescent bulbs.

Since plants use energy between 400 and 700 nanometers and light in this region is called Photosynthetically Active Radiation or PAR, we could measure the total amount of energy emitted per second in this region and call it PAR watts. This is an objective measure in contrast to lumens which is a subjective measure since it is based on the response of the subjects (humans). PAR watts directly indicates how much light energy is available for plants to use in photosynthesis.

The output of a 400 watt incandescent bulb is about 25 watts of light, a 400 watt metal halide bulb emits about 140 watts of light. If PAR is considered to correspond more or less to the visible region, then a 400 watt metal halide lamp provides about 140 watts of PAR. A 400 watt HPS lamps has less PAR, typically 120 to 128 watts, but because the light is yellow it is rated at higher lumens (for the human eye).

"Illumination" for plants is measured in PAR watts per square meter. There is no specific name for this unit but it is referred to as "irradiance" and written, for example, as 25 watts/square meter or 25 w/m2.

 

[Guest]

So what if you rotate between bulbs? If you got a switchable and one week MH, one week HPS through out the whole flower cycle? Could any positive come of this?

 

[Nostromo]

HeadyPete: I just decided that I will do my first grow with normal procedures and then, go for the second grow with a cool MH over the clones of the first grow, so I can compare each pheno. My third grow will use clones with both lights under one reflector. It will take a lot of time since I do not have lots of space, but I think it will be worth. I will report on the three grows.

 

[HeadyPete]

Sounds great Nostromo!

Yes, I like the looks of the Neutral Deluxe, Verite. I assume that the cool has more UV output, but I like the spectrum of the neutral for flowering supplement. It is also rated longer and has higher output than the cool. Time will tell...

 

[BigCloset]

My AK flowered much better under HPS than MH. I will never use MH for flower ever again, unless i already have at least four HPS. Most plants prefer about 90 percent red spectrum and just a little blue. This will differ a lot by strain though. Sativas will obviously like a little more MH than Indicas because of the area of origin. Just my 2 cents.