Colorado Med Growers, Unite

DannyGreenEyes said:

Wow, I spend two days arguing with Doogleef who's telling me that light is more important than anything else including root growth & formation. Now you're going to tell me that light don't mean shit. lol

Uncle ben has a few threads that covers light and according to him (he's considered somewhat of a guru) the only time you can have too much light is when you start to bleach the chlorophil out of your leaves. And that is something that you generally don't have to worry about with CFLs.

As far as light, since so many argue this way & that, let me just say that as far as HIDs, I'm sticking with Uncle Ben's info unless I find that he's wrong through my own experience. And as far as CFLs, I'm going to stick with Seymour Buds info unless I find that he's wrong through my own experience.

So if you have a problem with the advice I give on lights while I'm following their advice, please take it up with them.

And btw, when you say you go back to before all these fancy lights were invented, do you mean the CFLs? They've only been on the market for a few years if memory serves me right. Or do you mean LEDs? Or HIDs? Or Fluoro Tubes?

Actually scratch that last question, I really have no interest in arguing about lights. All I know is I have three 400w HIDs for 7 plants and I wish I had more. And I'll be adding CFLs during veg to get better coverage under the canopies. And after seeing the results from a grow done with a 400w CFL, I think I'm gonna get on for veg until I can afford a MH. And maybe add some CFLs or Fluoro tubes to that big CFL.

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Thanks Goofy and Jumbo for going out and trying to find the answer, you have set up the discussion for why CMH bulbs are best for our babies.

Lumens has absolutely NOTHING to do with what a plant wants, it is a measurement for how humans percieve light, not plants.

It has become a pseodo measurement for MJ growers simply because it is most usually printed on the package where the specs that actually matter are not.

I will post 3 pictures the usable spectrum of the sun, the part of it that plants use and the spectrum of CMH compared to HPS, you will be able to see why I like CMH so much.

and for those of you that want to know the proper terms for research here is a quote from a regular (non-MJ) garden forum (I keep tellin you these forums are great to lurk in, they have no myths, they experiment, and they exchange honest info)


Quote:
Hi Jon! You mentioned being fairly satisfied with the CRI of your present tubes, but less than satisfied with the growth of your plants. Of course, we need to consider all the cultural and environmental factors to determine what the problem is(fertilization, potting media pH, etc.) not just the lamps.


Brace yourself for some technical terms, but understanding them will make all the difference in choosing lamps. I was confused at first years ago, so don't feel alone if it happens.

There are 3 considerations in choosing lamps for plants, vs. lighting for the human eye: PAR, PPFD, and the duration of both. Let me explain. PAR (photosynthetically active radiation) are the violet, blue, and red wavelengths needed by the "higher" plants that most of us grow. These wavelengths appear dim our eyes even at high wattage or lumens, so "bright" lamps are an eye thing irrelevant to plants. The amount of the colours/wavelengths ROYGBIV in a lamps is revealed by its "spectral power distribution" graph (SPD). The company who makes the lamps will often fax the SPD graph to you if you cannot find it on the Internet. I've got piles of them. By keying in on your browser, "spectral power distribution of sylvania fluorescent lamps" you can see examples of what I'm talking about.

Then I compare these lamp graphs to the "absorption spectra" of plant pigments, namely chlorophyll a, chlorophyll b, and the carotenoids - particularly beta-carotene. Plant pigments will either reflect off the wavelengths that your lamps provide or will absorb them for photosynthesis. They reflect off most of the green, yellow-green, yellow, and yellow-orange wavelengths that just so happen to appear as bright to human eyes. Absorption spectra graphs reveal that violet, blue, and red (PAR) are what are needed for photosynthesis, and CRI of lamps don't indicate what colour wavelengths are in a specific tube. "Cool white" and "warm whiate" terminology is equally useless! Light intensity in watts or lumens do not refer to how much PAR is available to a plant, and is also irrelevant to how much PPFD (explained next) exists.

The measurement of how many usable photosynthetic wavelengths actually reaching the leaves (its density) is called PPFD, or photosynthetic photon flux density. This is about usable photons. And if the PPFD is not enough in your lamps when the PAR is relatively good, many plants can make up their need for a daily amount of carbohydrate production just by settin the light timer to remain on another 2-3 hours.

This can be a lot to digest, so I'm going to stop here. Again, feel free to let me know what you can't grasp.
Respectfully, John_Z.

He puts it so well that quoting him was easier than me typing it out for you

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doogleef said:

This is a much better graph for a decent HPS. CMH are still relatively new and I've not used them myself. It is HID so I have hopes but a lot of their marketing sounds suspiciously like LED marketing. Bang for the buck.

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doogleef said:

This is a much better graph for a decent HPS. CMH are still relatively new and I've not used them myself. It is HID so I have hopes but a lot of their marketing sounds suspiciously like LED marketing. Bang for the buck.

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MacGuyver4.2.0 said:

Been using them for 6 years now, with great results. Will check out the CMH ones now as well. Thanks for the info, even though I already had the charts from EYE.

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riddleme said:

Hey Danny not gonna argue at all, I have no reason to I break the myths every day in here some listen some don't, some simply don't want to hear the truth. but if your truely following Uncle Ben (who is involved in my class) then here is a quote from him for ya

Like I've said in other posts, there is a light saturation point whereby "more is less". A plant can only use so many photons in a day, after that bad things start happening, like photosynthesis is curtailed, chlorophyll bleaches out, etc. Check this graph out: http://www.marietta.edu/~spilatrs/biol103/photolab/saturati.html

as posted by ub

It was because of folks not listening to UB that I started the class in the first place

Not for one minute saying that your 400 watter's are bad just that you need to learn how to properly use them

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doogleef said:

Cool graph. Primary liming factor of photosynthesis in cases of light saturation is available co2. Sum of the parts and what not....

Here is my take on lighting.....

Density target = 50 watts per sq ft. This in NOT a hard line number. You can get good growth with 20, it will just be slower. 50 is agood number to be at to try and reach for the 1 gram per watt level. I know lots of people who run at 75 watts per sq ft with no bleaching but they get a smaller return per watt so is it worth it? With co2 added to 1500ppm you greatly increase the ability for increased light density but to really do co2 properly requires controllers, regulators and either a tank with refills or a generator with the inherent heat issues.

Veg = CFL is fine, T5 is better, MH is best. If you have to use a single light for the whole run go HPS and get a lamp with the added blue arc. A "superHPS" or just add a single daylight CFL to your HPS veg setup.

Bloom = HPS all the way. CFLs can be used but HPS is much more efficient in the lumen to watt ratio and gives much better end bud structure in most cases.


LED - Decent supplimental lighting, not a main light source. Adding a GOOD LED panel (1 watt per lamp) is about the same as adding another 600W to your space but they last for 20 yrs and cost nada to run. Over time, they are they best buy in supplimental but the initial price is still an ouch for quality gear.

UV - Its hard to argue with the Frank studies done on the effect of UV lighting on tric production in late bloom. That said, we live in an environment where the humidity is always low forcing a frosty finish to all my nugs anyway.


Grow on, CO!

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EdGreyfox said:

Hey all,

I'm in Denver and I've just started my first grow. It's an organic soil setup for a few "opium" clones, and i'll be adding pics as the grow progresses (not much to see at the moment). I'm wondering, where's the best local source for good clones from strains like train wreck, northern lights, white rhino, etc, at reasonable prices?

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DannyGreenEyes said:

Thanks for that info, +rep

Through the info on that page I can now see the relation between light & CO2 a little better.

Unfortunately I'm still stuck with the bleaching of the chlorophil as the only sure indicator that too much light is being used (or possibly not enough CO2).

The only other way I can think of is to keep track of daily growth in relation to watering so when more light is added you can compare the new results and the old results to see if it's helping, or if it's just overkill.

Also, adding light & then changing your light scedule to increase the "dark time" may help with growth. But this is much harder to claculate other than by trial & error. In other words, if you're on a 24/0 schedule and you double your light and change to a 18/6 schedule. The growth may not change in the "light time" but the growth in the "dark time", which would be mostly root development from what I understand, would be next to impossible to measure.

The info is good, don't get me wrong. But I still see trial & error the only real way to determine when you have too much light.

And with CFLs, unless you have an entire wall full of bulbs, or multiple 400w CFLs, I don't see anyone reaching the point of saturation.

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riddleme said:

In my class I asked if your growing in soil which meter is more important a light meter or a ph meter. The answer was a light meter because soil is ph tolerant.

Successful grows are a perfect balance of all the parts and the plants only need 50 watts or 3000 lumens (niether of which is a complete measurment but rather an approximation without doing further research) per square foot. Giving them more than they need without adjusting the other parts causes stress to the plant in any number of ways, Bleaching, transpiration, heat stress etc etc etc

In the class I am teaching everyone how to dial all the parts in as I have done to prove that you can get big tight nugs with one cfl (if done right)

Please feel free to read the info in the class NooB Advice link in sig and benefit from it as I know you will because you have proven to me that you actually really WANT to learn this stuff

PS Doog is dead on and knows his shit, trust his advice

On a lighter note I went to Paulinos today and ended up teaching a class there which I have to admit was a lot of fun

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DannyGreenEyes said:

Wouldn't the plants surface area have anything to do with it?

I mean one 5gal container might have a 12" plant with a 5" circimference and another might have a 24" plant with a 12" circumference. I would imagine that the bigger plant would have a higher light saturation point because it has more suface area to absorb it & to absorb CO2, and more roots to intake water & nutes.

So shouldn't you be taking cubic feet or cubic inches into consideration?

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EdGreyfox said:

Riddleme,

So what adjustments would you make if you were using a 400W Mh that was putting out somewhere between 6500-7000 lumens per sq foot? The area is one half of an 10l x 2w x 9h walk in closet thats doors are being left partially open for airflow purposes (gap on each end with a fan forcing circulation through one side and out the other. Plants are in fox farm soil, 3 gallon pots, and are freshly transplanted clones ranging from 3.5-5 inches tall. Temp is between 69-75, but I'm not sure on humidity (still need to pick up a monitor).

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Arvada said:

I bought a 600 w EYE Hortilux ES bulb.(HPS)
I was planning on useing it for flowering only. They are three times the price of standard HPS bulb. Used for flower only, is it worthwhile?

Also, I bought T5 flourescent 6500 k High Output bulbs for: clones, germination seeds, veg grow state, and mother plants.
Question- Do the T5 tubes come in std output and high output? Or is any T5 tube the high output type?

EDIT: I found out there are both types of T5 tubes.

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DannyGreenEyes said:

Sorry Doog, I think you may be a bit off on the sq ft to wattage ratio.

When I started veg I had 7 plants in 9 sq ft.. The growth under one 400w MH was OK. Under one 400w MH & one 400w HPS it was better. And under one 400w MH & two 400w HPSs it was better still.

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By your calculations adding the second light should have yeilded only a minimal increase in growth, and adding the third light shouldn't have done anything at all.

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