All BS set aside CMH yields

im running 3, 315 wright now and next run under a 1k hps to compare yields... no way can 3 315 watt cmh compare to 2 1k hps thats 945 watts compared to 2,000 watts...however 945 watts cmh easily cover the same space or larger than a 1k hps...i believe the claim that 1 315 watt cmh is comparable to 1 600 watt hps is exagerated.. 1 315 watt cmh can cover the same area as 1 600 watt hps at 2 ft above canopy but yiield will be a bit less..the grams per watt is higher with the cmh tho.

TheChemist77 said:

im running 3, 315 wright now and next run under a 1k hps to compare yields... no way can 3 315 watt cmh compare to 2 1k hps thats 945 watts compared to 2,000 watts...however 945 watts cmh easily cover the same space or larger than a 1k hps...i believe the claim that 1 315 watt cmh is comparable to 1 600 watt hps is exagerated.. 1 315 watt cmh can cover the same area as 1 600 watt hps at 2 ft above canopy but yiield will be a bit less..the grams per watt is higher with the cmh tho.

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Would you accept the equivalence of 400W or 450W HPS to 315W CMH?

When replacing hps with the 315's anyone trying to replace 2x 1000's with 3x 315's is setting an unrealistic expectation and buying into vendor hype. It's ridiculous to think they would yield the same imo. That said, if you're starting from scratch or looking to replace hps, the 315w form factor works in your space and your not willing to invest the kind of money needed to replace it with COBs, I'd still recommend the 315's. Just replace watt for watt and you'll get a 20-30% increase without changing anything else. We did that with my son's setup, he's been crushing his previous numbers by an average of 25% better quality yield which covered the investment in his first full run. That's a win in my books.

Another win imo is straight up replacing a 400w. Many running a 400 will be in a relatively small space and not only save the draw but save and be able to maintain the environment easier due to less overall heat. Although in a small space I'd personally go COBs, if someone is not wanting to DIY or invest in a commercial COB panel, the 315w is a good option in between the two.

ttystikk said:

Would you accept the equivalence of 400W or 450W HPS to 315W CMH?

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i would say the 315 is more equivilant to 450-500 watts hps.. as for coverage each 315 will cover a 4x4 space well,,so when they are claiming its comparable to a 600 watt hps its the coverage that is the same..

TheChemist77 said:

i would say the 315 is more equivilant to 450-500 watts hps.. as for coverage each 315 will cover a 4x4 space well,,so when they are claiming its comparable to a 600 watt hps its the coverage that is the same..

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There are some who say the cross lighting from many of these will make up for running them at twenty something watts per square foot. I'm skeptical of this claim but they say they did their homework.

Carolina Dream'n said:

That is what I'm saying. Everyone I've talked to that has replaced 2 1000s for 3 315s were only pulling 1.25-1.5 lbs per 1000w.
I've yet to see a grower pulling 2-2.5 lbs per 1000 changing to them at the same 2 1000s for 3 315s, they do 3 315s per 1000, and claim to be yielding 30 to 40% more with 3 315s than a 1000.

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Right. The 315watter is a fine addition, allowing for more options, can be a great fit for some growers, but they aren't "that" great. They make 400w hps obsolete imo, replacing a 1000watter (boost to 1100) with 3 separate sets however is already not attractive if you run many lamps.

GroErr said:

Just replace watt for watt and you'll get a 20-30% increase without changing anything else. We did that with my son's setup, he's been crushing his previous numbers by an average of 25% better quality yield which covered the investment in his first full run.

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If someone pulls 0.9gpw with hps and 1.2 with cmh that's a 30% gain yes. Yet others grow (easily) over 1.0 gpw with hps in which case it evens out. Not saying your percentage are wrong or anything, but they mean little to nothing without the hard numbers they are based on.

I don't believe cmh results in better quality by default.

Additionally, to an extend when you spread out the light more than ideal for let's say max oz per sqft, you can increase the gpw relatively (with the downside of getting more leafy bud) skewing those percentages even further. I have a limited space and running low ppf isn't going to increase the total yield from that space. If I run my 600w on 4x5 I will get more in total and higher gpw than I get on 3x4, but also more leafy, more branches, and less swollen, less meat, less of the part I care about. Frosty leaves is nice, but not when it's a trade off with swollen calyxes ("bracts", which have the highest concentration of trichs). I would run them on 3x3' max, or like chemist even less, 2x3 per plant.

And yes, the guy with the 315watters in the warehouse can run them so high up because of the overlap. In dutch green houses they are attached to the ceiling, often over 10 feet. People who bring up inverse square law tend to be the ones who miss the obvious reason why that works...photons don't go poof...overlap...

In fact it is much better for light penetration. If cob leds would have a much wider angle you could hang 20 around the center of the ceiling, aim them so they each individually cover the entire grow surface, all overlapping but from a different angle (directly affecting penetration into the crop) and you get roughly the same ppf as when you would spread out the cobs, aim them down and cover only a portion.

So, light distance is highly overrated, and so is the inverse square law that applies to a single omnidirectional lightsource.

Sativied said:

If someone pulls 0.9gpw with hps and 1.2 with cmh that's a 30% gain yes. Yet others grow (easily) over 1.0 gpw with hps in which case it evens out. Not saying your percentage are wrong or anything, but they mean little to nothing without the hard numbers they are based on.

I don't believe cmh results in better quality by default.

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Yes, true enough. But if you go from one tech to the other and gain without doing anything, then up your game, there's even more on the table to win.

Quality is somewhat subjective. If I want the best quality I run them under LED's but that could be perception, I don't have access to testing. The LED buds always seem to bring out more frost and terps when I do a run, same strains I'm running under CMH though.

@ttystikk I like that low frequency square wave tech. if I understand correctly, this would do much the same thing as DE tech in that I it gets rid of the high frequency flashing?

febisfebi said:

@ttystikk I like that low frequency square wave tech. if I understand correctly, this would do much the same thing as DE tech in that I it gets rid of the high frequency flashing?

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DE is just a different lamp. It gets its efficiency advantage from high running temperature, this directly from someone who worked at GAvita. Now you know why they run so hot, lol

High frequency digital ballasts are already much more efficient than magnetic ballasts. The flickering is so much faster it disappears. Yet EYE does have a Platinum series ballast that purports to be a low frequency digital square wave specially optimized for SE HPS thouies. They're stupid expensive so no one I know of has bought one and tested it.

So I wonder then, why the eballast revolution was satisfied with the high frequency version of the mag ballast. I'm sure most people could care less about the RFI but there are some things to consider. You might notice more static on your radio stations, and such. I bring this up becausae when I was a kid I had to study a whole section of a big ass Ham Radio licensing manual, on what else, but "the dangers of Radio Frequency Interference. when using radio transmitter 5watts and higher. Lets pretend for a second that we are not using an eballast, and HID light. Instead we are running a radio station that broadcasts from the top of a mountain to the whole city. The transmitter would be throwing out enourmous amounts of RFI, at huge wattages to reach all those people. If you were the maintenance guy on this transmitter, you might worry about the health issues associated with being in close proximity to that much RFI. There is a reason your talk show host is not up on the mountain, thats because its dangerous. Now im sure you all are scratching your head thinkng "what does this have to do with anything?' But running an eballast or many of them at many KW is not that much different. coming out of our ballast is a nice long cord running to our bulb. I would imagine that setup makes a fine antenna to transmit all the RFI to the whole block, and since we are not trying to run a radio station, thats a bad thing. could even be a health risk. I wouldnt be surprised if it screws with the plants too, as they are living things as well.
Assuming the 5watt and higher radio transmitter is enough to get attention by the government as having health risks? what about the row of 1kw dig ballasts, most of us are running 12+ hours a day. The likely hood of any sort of "sheilding" is very low. I wonder if anyone knows how the RFI output from a 1kw eballast is like when compared to an FM/VHF/UHF radio transmitter.
@ttystikk maybe you might know more about this?
I heard of one guy who kept geting his cable internet cut off cause they were getting interference from his address. apparently a switch back to his old mag ballasts remedied the problem. It sounds like we should all be using low frequency square wave instead. The tech has been around for a while it seems like... just cheaper I guess, and the promise of slightly less power draw, and "digitalness" was enough to convince most people.
too bad the only one available for non specialized bulbs, has to be too expensive to even research. But if we had all demanded it back before eballasts, the tech would be available at reasonable prices for non specialized products. Instead the commercial lighting companies are keeping the tech for their own products.
Also , what about DE ballasts, do they oscillate RF in the same way?

febisfebi said:

So I wonder then, why the eballast revolution was satisfied with the high frequency version of the mag ballast. I'm sure most people could care less about the RFI but there are some things to consider. You might notice more static on your radio stations, and such. I bring this up becausae when I was a kid I had to study a whole section of a big ass Ham Radio licensing manual, on what else, but "the dangers of Radio Frequency Interference. when using radio transmitter 5watts and higher. Lets pretend for a second that we are not using an eballast, and HID light. Instead we are running a radio station that broadcasts from the top of a mountain to the whole city. The transmitter would be throwing out enourmous amounts of RFI, at huge wattages to reach all those people. If you were the maintenance guy on this transmitter, you might worry about the health issues associated with being in close proximity to that much RFI. There is a reason your talk show host is not up on the mountain, thats because its dangerous. Now im sure you all are scratching your head thinkng "what does this have to do with anything?' But running an eballast or many of them at many KW is not that much different. coming out of our ballast is a nice long cord running to our bulb. I would imagine that setup makes a fine antenna to transmit all the RFI to the whole block, and since we are not trying to run a radio station, thats a bad thing. could even be a health risk. I wouldnt be surprised if it screws with the plants too, as they are living things as well.
Assuming the 5watt and higher radio transmitter is enough to get attention by the government as having health risks? what about the row of 1kw dig ballasts, most of us are running 12+ hours a day. The likely hood of any sort of "sheilding" is very low. I wonder if anyone knows how the RFI output from a 1kw eballast is like when compared to an FM/VHF/UHF radio transmitter.
@ttystikk maybe you might know more about this?
I heard of one guy who kept geting his cable internet cut off cause they were getting interference from his address. apparently a switch back to his old mag ballasts remedied the problem. It sounds like we should all be using low frequency square wave instead. The tech has been around for a while it seems like... just cheaper I guess, and the promise of slightly less power draw, and "digitalness" was enough to convince most people.
too bad the only one available for non specialized bulbs, has to be too expensive to even research. But if we had all demanded it back before eballasts, the tech would be available at reasonable prices for non specialized products. Instead the commercial lighting companies are keeping the tech for their own products.
Also , what about DE ballasts, do they oscillate RF in the same way?

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You clearly know more about the subject than I do.

DE is just a lamp. In all other respects it's a completely conventional high frequency digital ballast.

This problem will resolve itself because the next generation of drivers will be running DC current.

for an experienced grower what is the best gram per watt achieved with hps? ive heard of people pulling 2 gpw but have never seen this in person.. the best ive seen in the big grow op up here were tjhey are running a gymnasium size room with 1,000 watt hps they say they get 1.7 gpw consistently, however im talking regular people on say a 4ft x8ft table,,best gpw??
as for the cmh, i was happy with my first run, and i could have done better.. 2 315's over a 4x6 table worked well getting 400 grams per 315watt, that said this run using 3 315's over the same area ill get more weight but feel i wouldve been better with a larger area say 3 over a 4x8 table. , i think running 945watts over the 4x6 table is not getting the most out of these lamps,,just squeezing them in..with time and experience i believe 1.7-2 gpw is achievable with the cmh..

TheChemist77 said:

for an experienced grower what is the best gram per watt achieved with hps? ive heard of people pulling 2 gpw but have never seen this in person.. the best ive seen in the big grow op up here were tjhey are running a gymnasium size room with 1,000 watt hps they say they get 1.7 gpw consistently, however im talking regular people on say a 4ft x8ft table,,best gpw??
as for the cmh, i was happy with my first run, and i could have done better.. 2 315's over a 4x6 table worked well getting 400 grams per 315watt, that said this run using 3 315's over the same area ill get more weight but feel i wouldve been better with a larger area say 3 over a 4x8 table. , i think running 945watts over the 4x6 table is not getting the most out of these lamps,,just squeezing them in..with time and experience i believe 1.7-2 gpw is achievable with the cmh..

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The best I've ever done with hps is 1.3 gpw with 1000w DE. Took me years to get to that. First run with 315s was 1.2 gram per watts. Damn near felt like I had to relearn my plants, they acted completely different under the 315s.

I'm coming closer and closer to the conclusion that these are in fact more effective gpw than an hps.

ttystikk said:

You clearly know more about the subject than I do.

DE is just a lamp. In all other respects it's a completely conventional high frequency digital ballast.

This problem will resolve itself because the next generation of drivers will be running DC current.

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thatll be something, for sure. Eliminating AC from the picture. Assuming LED doesnt take over entirely before then. since LED driver is already DC, but that would require the right products being available at the right time. for a fair price, and we are far from there yet. right now, of the thousands of led's avaible, the COB is the first I have heard anything good about. I understand the draw to LED, I would love to have half the power draw, but I am waiting for the next round of tech to come around, now that there is something decent on the market. I might be willing to experiment with the diy COB, but for now, after spending a lot of time researching it, i'v decided against CMH, in favor of DE bulbs, and focal point reflectors, on existing drivers. which seems to make the most sense at this point in time. its actually going to cost the same per light as cmh.
There is something to be learned from all this, and I think everyone can agree that we cannot depend on horticultural companies to tell us the truth, because the truth is not their friend. Its up to us to educate ourselves, which is not easy, and very time consuming, assuming your not an electrical engineer, which most of us are not, myself included. We need to follow what the commercial lighting manufacturers are doing. When you consider most of the only inovative new products in HID horti lighting, came from Philips, and copied by others. I am mainly talking about double end, but the latest Agro Elite 315 looks promising, and even the older cmh were very innovative for their time, but has been argued to death whether there is anything to be gained at all from anything other than HPS. It is obviously difficult for us as a group to agree on anything when we are getting 100 different sources of misinformation telling us how to spend our next fortune on their cheap tech.

There are so many more HID lamps out there than people realize. They light factories, showrooms, musuems, and even street lights, and they are all switching to full spectrum lighting, simply because of the quality of light percieved by humans is best when closely matched to sunlight.
My latest reserach project after beating the CMH topic to a pulp, and every other philips product of consequence. I stumbled across another commercial lighting manufacturer called Venture, and they have some very interesting tech indeed. Again, I am not trying to advocate any type of lighting, only to share information. There is a new breed of FS MH's apparently, now that are advertising the same life as LEDs, and a spectrum that is almost completely flat all the way from UV to IR(minus the UV shield), looks more like a plasma or something than a MH. 40khrs from a single bulb on a matched electronic square wave ballast up to 400w. I dont even know what to say to that.. 40k hours is something I will have to see for myself, and 26k hrs on one of their matched mag ballasts and maybe 20k on retrofit pulse start ballast, all at 90% lumen maintenance over their life. And they make them up to 975w on mag ballast, with the same spectrum. last time I checked they are only about $50 for a 575w ballasts are around $100 but require some assembly...lol. they do have enclosed ballasts, and enclosures for their kits, but i'm sure thats a lot more costly. Thats just one of their products, they have a lot more I havent even had time to look at, including PAR LED's. Its too bad they refuse to get directly involved with Agri business, because I think they could very well have a lot to offer us in ballast tech if nothing else. They have a huge international commercial market to attend to so they made a child company they call sunmaster, so after some technical discussions with Venture's MFR reps I was refferred to sunmaster. who is apparently made by Venture lighting, and offers a simliar spectrum on a 6k bulb instead of the 5k bulb from venture. But the real difference is that it can run on any eballast or pulse start MH mag. Which may seem like a good thing, limits you to 5k hrs and twice the cost per bulb, because of our crappy ballasts we cannot get the same life out of a seemingly similar bulb. I would rather pay half the price for bulbs and spend the rest on ballast tech that equals 26khrs-40k hrs. keep in mind the spectral output may degrade over time, but venture apparently is the supplier for some 80% of gases used in full spectrum bulbs made by other companies, so it sounds like they know what they are doing. we would need a spectroradiometer and some serious time to know for sure.

So it looks like even streetlights(you know the ones that look real white) are running better quality light than we are, which is pretty sad if you ask me, we definitely do not have the best tech available, and we should be looking elsewhere. This is why I have been researching commercial lighting. It has been said before that CMH is old news. CMH was the first step anybody has taken out of the horti market for lighting, which is likely the reason people argue this topic to death on a daily basis.

We are so stuck in our ways, we have changed the genetics of the plant to favor HPS further skewing our data, for any other kind of lighting. Since everything is crossed with everything these days, we will probably never get rid of those traits entirely even when everyone is running full spec led's or hid's whatever tech leads this market.

We really should move the discussion to a new "lighting tech" thread since the discussion has become about more than just CMH. So we can all share the newest tech on the market. really we should have a whole organized section for lighting tech where we can discuss each tech in detail.

The attached spectral chart is for the sunmaster 6k bulb. I'm gonna try one and maybe get some use out of my cheap eballast while were at it, and we will see how the spectrum performs, and then maybe invest in venture bulbs and drivers.
to view the venture spectrum (very sexy) look to page 9
http://www.venturelighting.com/On-LineCatalog/Venture_Lighting_Interactive_Catalog_v1.pdf

My friend runs this led i think he called it a black dog or a black something. Anyway he swears he gets better yields than hps. Personally i would never run anything oth than a hps for flower

MrStickyScissors said:

My friend runs this led i think he called it a black dog or a black something. Anyway he swears he gets better yields than hps. Personally i would never run anything oth than a hps for flower

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Commercial warehouses in Colorado ate switching away from HPS in droves. Many are installing 315W CMH lighting. That itself should tell you everything you need to know about HPS.

@febisfebi too long! People gonna get lost in posts like that, lol

Anyway, the reason I said the next generation of ballasts will be running DC current is precisely because they'll be driving COB LED chips!

HID tech is over for all planning purposes. COB LED is on its way and it's a better light in damn near every way. It's just a matter of time before it's cheaper up front as well as less expensive to operate.

I waited out the blurple LED era, too. Those units did us early adopters a favor by scaring off the uninformed and holding back the tide of manufacturers.

The guys here have done excellent work testing chips for efficiency and spectrum, discovering just how beneficial current droop is for our purposes and coming up with ready to use configurations for the relatively uninitiated such as myself.

I'm using a Venture MH in my finishing zone right now. Decent lights, but they are the low cost producer. Sunmaster HPS sucks, lol. You want a top quality budget HPS, get Plantmax thouies.

I know I missed something... try not to bury your points quite so deep? And pass that joint, cuz that shit's gooooooood! Lol

ttystikk said:

@febisfebi too long! People gonna get lost in posts like that, lol

Anyway, the reason I said the next generation of ballasts will be running DC current is precisely because they'll be driving COB LED chips!

HID tech is over for all planning purposes. COB LED is on its way and it's a better light in damn near every way. It's just a matter of time before it's cheaper up front as well as less expensive to operate.

I waited out the blurple LED era, too. Those units did us early adopters a favor by scaring off the uninformed and holding back the tide of manufacturers.

The guys here have done excellent work testing chips for efficiency and spectrum, discovering just how beneficial current droop is for our purposes and coming up with ready to use configurations for the relatively uninitiated such as myself.

I'm using a Venture MH in my finishing zone right now. Decent lights, but they are the low cost producer. Sunmaster HPS sucks, lol. You want a top quality budget HPS, get Plantmax thouies.

I know I missed something... try not to bury your points quite so deep? And pass that joint, cuz that shit's gooooooood! Lol

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Oh I read the whole thing ! Interesting.......Looking carefully at the whole thing.

Carolina Dream'n said:

Damn near felt like I had to relearn my plants, they acted completely different under the 315s.

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I remember posting something to this effect when I first switched to these 315's. It takes a couple of grows to get used to them, the plants react differently, not a bad thing but definitely different. They mature faster and set buds quick, in turn they get very thirsty/hungry in that transition period which takes some adjustment in watering/feeding them.