All BS set aside CMH yields

is it true or not

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    118
Merlin34

Merlin34

Well-Known Member
febisfebi said:
Very good point. Many folks think that the spectral output degrades at the same rate no matter who made the bulb, but I have an old HPS-Retro-White thats still going strong, made in 2011. not exactly sure how much use is on it, but im sure its significant. still outperforms any 400w mh I have ever seen, even comparable to a 600, just less coverage. Have you experienced any degradation in crop quality over the 20k hours CMH's are rated for, or have you ever used one even close to that long?
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I'm not close to 20k, I'll probably start with the switching / change out at 15k

Mile High Colorado
 
Tim Fox

Tim Fox

Well-Known Member
what i am noticing ,, is this, all the new led start ups may go out of buisness if it turns out the cmh 315 performs better?
 
firsttimeARE

firsttimeARE

Well-Known Member
315w/942 (fresh out of box) day 20 same strain
SAM_3227.JPG SAM_3234.JPG

vs.

600w Ushio HPS (3 cycles old) day 35 same strain
SAM_3205.JPG SAM_3206.JPG

They run way cooler. The light is so much more crisp. Lights on photos don't look like garbage. The stretch is less IMO.

Im gonna switch out my HPS after this grow. Go with a 860w allstart in an OG vert
 
firsttimeARE

firsttimeARE

Well-Known Member
Not with this grow I won't do it. For a few factors. A.) I outgrew my scrog B.) cookie strains and crosses are notoriously terrible yielders. But it definitely has potential.

Im thinking you could pull over 1.5gpw with the right strains. Maybe 2gpw.

(4) 1.5ftx1.5ft screens with RDWC producing 4-6oz per thats 1.4gpw at the low end and 2gpw at the high end.

i've pulled 8oz off a 600w in a 2x2 screen regular DWC. thinking 4-6oz is definitely possible in a 1.5x1.5 screen.
 
2easy

2easy

Well-Known Member
Tim Fox said:
i have yet to see someone yeild over 1 gpw with a cmh?,, can it happen,, if not whats the hype?
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1 gram per watt is easily achievable with the 315w. probably more so than any other light i have used. however to reach a gram per watt with any light your going to have to master canopy control and space management. Gram per watt is a terrible guideline for how well a light works because there are so many other aspects that affect the end result mainly the grower being the number one set back.
 
febisfebi

febisfebi

Well-Known Member
we will have to see what gpw can be done with a DE + supplemental, vs all 3100k cmh. but you guys are using way less overall watts in a given space. it will be interesting to see if the extra power draw from the supplemental brings down the gpw of the DE significantly enough to make the all CMH option a better choice. Personally I think the light created by two different lights will almost always be a more complete spectrum than any one single kind of bulb, when we are talking about HID anyways, so there could be potential for a better product with the pair even if the gpw is less. I think the quality difference has a lot of it has to do with the deep blues and UVA that these types of setups include. I know glass blocks a lot of uvb and lets some uva thru, not a lot, but its important. Thats the one thing I want to see LED manufacturers come up with a solution for, and UVB too while they are at it. I know they are working on it.
 
firsttimeARE

firsttimeARE

Well-Known Member
Merlin34 said:
Well a pound a 315 is a lot more than a gram a watt

Mile High Colorado
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I think a lb is totally reasonable off a 315w with the right strains.

If I can find a plant worth keeping i'll try to shoot for that the next grow. First grows with plants are always tough to scrog right as you have no idea of the stretch it has.
 
TheChemist77

TheChemist77

Well-Known Member
febisfebi said:
Pretty impressive. Congrats on getting that beast up and running!!
What I am trying to discern, is if there are real advantages to running say 5 (fairly expensive) 315w lights, when compared to simulating the spectral output of CMH with for example 2 DE 1kw lamps paired with supplemental 1000 or 600w Ushio Opti-Blue or similar lamp to cover the rest of the spectrum and end up with something similar to 3100k CMH in terms of total spectral output in the room. This is where we need a side by side comparison. We all know that running full spectrum lighting is going to produce a better product, so comparing to straight HPS (while informative) is not really an apples to apples comparison. Since so few people seem to be supplementing their HPS its difficult to come up with the justification for investment in CMH to replace something like this, since they should be fairly similar quality of light. Given that, (which is not a given, but a speculation) I would further speculate that the 3kw of DE HPS/Opti-blue could potentially produce a similar GPW with similar THC% as the 1575w of 3100k CMH, covering the same area like you are doing. The real difference is cost. In my estimations, it would cost significantly more to get just over half as many watts.

CMH is supposed to be more efficient at converting electricity into usable plant light, so the question then is how much more efficient, and is it worth spending big $$ on. It may be that the savings would come more from decreased cooling costs, so we have to take that into consideration as well. We have to consider the total draw of the room, when doing a head to head comparison.

From what I understand, 1.5 gpw is attainable with plain DE HPS. when you throw the supplemental light in there, the actual GPW might be slightly less, since we are counting watts, and like @Merlin34 said the 6-9% thc level increase is what the supplemental light will be primarily doing for you.

Hopefully someone out there has the time and resources to be able to do a real comparison like this.
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i ran 1 600 watt hps and 1 600 watt mh over my 4'x6' table as we know the 2 together produce a better spectrum.. then i ran 3 315 cdl's over that same area.. gram per watt was better with 945 watts cdl than 1200 watts hid and the bud produced was just as frosty..
 
TheChemist77

TheChemist77

Well-Known Member
my first run with cdl got 1.4 gpw far better than my hps or hps/mh combo runs.. every run since has gone up im now getting 1.5 gpw
 
febisfebi

febisfebi

Well-Known Member
TheChemist77 said:
my first run with cdl got 1.4 gpw far better than my hps or hps/mh combo runs.. every run since has gone up im now getting 1.5 gpw
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First off I think you mean CDM, not cdl, and please don't take any of this as an attack on you personally.

I'm not sure what kind of MH you were using, I know a lot of people have tried various hps/mh combos, but that is very different when you are talking about a regular old SE HPS, and a regular old 600w MH. I can tell you right now though that a 1:1 ratio of SE HPS and standard MH (as you obviously can tell) is not a comparable lighting system to 3 CMH. The magic number is supposedly around 20% blue, which is why the 3k cmh is (arguably) the preferred all in one flowering light when it comes to CDM/CMH. So you were definitely overdoing it on the blue side, especially when you are talking about your GPW. As I described earlier your GPW is going to come from your HPS. The supplemental is going to raise your quality, and the extra power draw could hurt your overall GPW extensively. So in that case, using a full 600w of supplemental light is going to bring your GPW way down. in fact I would venture to speculate that even 2 315w 3k CMH would still beat out the 1200w combo in GPW. This is why @Merlin34 is able to run a commercial operation with around half the watts covering the same area, and getting better quality, which in his case makes a lot of sense, since the power draw of commercial operations is so much more of a problem at that scale, and quality dictates the crop value over quantity.

I am trying to compare performance of top quality DE HPS, which is a whole different animal than old SE HPS, both in spectrum and overall growing horsepower. Pairing those with Top quality Supplementals, at a 2:1 or even 3:1 ratio. Now this could be anything from for example, a Hortilux blue (which I would personally not suggest for limiting cost or power draw, as it is lacking in both) or similar FS MH, there are other more efficient options in this family of full spec. Similarly, it could be a 4200k CMH, or in my example, an ushio opti-blue, or any of 10 other options available from different mfgs. I figure the opti-blue is a good solution, to the extra power draw, since it is more focused on the parts of the spectrum that the DE is lacking in, and has significant UVA output. But I am still testing all three of these types of supplementals before I make a final decision on which works best. But what I don't have to compare is a roomful of 3k CMH lights.

I just stumbled upon something new I wasn't aware of. I knew that Ushio started making CMH, but I didnt realize they were not just a clone of the Philips. look at the spectral chart of this bad boy. >95CRI: http://www.ushio.com/files/specs/hiluxgro-CMH5002537.pdf

Could potentially be a little lacking in the UVA dept, compared to some other options, but they only go down to 380 on the chart, so we dont really know for sure, but it looks like a steep drop at that point.
 
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