Opinions on CMH lighting for flower

[Nitegazer]

This may have been posted elsewhere, but I thought this made a good case for CMH. I only have a personal 400w grow and am leaning towards getting the Philips conversion 400w bulb-- cheaper than good hps and far better par.

 

[MarWan]

I used a Philips 330 cdm for veg in a 2x3 space (as a replacement for a 400w mh), and the growth was crazy almost like growing under the sun; huge fan leaves , short inter-nodes and thick stems.

when I flowered my plants I used one 330 cdm and one 400w hps in a 4x4 tent, the plants that were directly under the 330 had more frost on them, it was the best harvest I ever got.

I just ordered 2 advanced ballasts and 4 315w cmh bulbs which i will be using for flower.

 

[frontline]

I've been running my 315 3100k Philip's bulb in an old 400 hps ballast ,not as efficient but sure boost's trichomes .

 

[skoomd]

I've been running my 315 3100k Philip's bulb in an old 400 hps ballast ,not as efficient but sure boost's trichomes .

Old thread haha.

Yes, CMH will definitely boost your trichome production over traditional HPS, ive seen in several tests that it increased THC a few percent too.

But they're quite expensive compared to hps, a 315w CMH is only equal to 400-450w of HPS in terms of output. I have 3 friends who grow using CMH, and the usual 315w CMH in a 3x3 space seems a little lackluster. Running a 630w (either double ended or 2x 315w) in a 4x4' seems to get them bigger buds and a better yield for the space.

Just my $0.02, ive never used CMH myself but ive been tempted to try it. They undoubtedly grow better quality bud than HPS though!

 

[frontline]

I'm running 2 315w cmh 3100 Philips with a 400 hps , sometimes a 600 hps on a 3x7 area , 2-3x3 flood tables. If I don't run hps I have to use a small heater to keep temps around 80 . Hps is in middle . Went to cmh to get power bill down. Will see in a few week's .

 

[skoomd]

I'm running 2 315w cmh 3100 Philips with a 400 hps , sometimes a 600 hps on a 3x7 area , 2-3x3 flood tables. If I don't run hps I have to use a small heater to keep temps around 80 . Hps is in middle . Went to cmh to get power bill down. Will see in a few week's .

That's a solid light setup. From what ive seen, HPS + CMH always makes for some delicious looking buds that swell up quite fat. DEHPS + CMH is unreal, but the electricity cost is nuts.

I want to try an LED + CMH setup soon. I want to use the CMH as a quality booster and the LEDs more for raw photons. Though seeing the quality of what i got flowering under my 600w strip light right now, I dont know if ill see much difference haha.

 

[Flagg420]

Get yourself 1000watt double ended and don't get fooled by marketing. There's a reason big companies use just that, sometimes supplemented by 300watt plasma's. Cmh gives you airy buds and led still doesn't yield like hps.

1000w DE kits are great if you have a warehouse... but if you got 8ft ceilings, its gonna be hell.

 

[skoomd]

1000w DE kits are great if you have a warehouse... but if you got 8ft ceilings, its gonna be hell.

I'd rock a 630w DE CMH over a 1000w DE HPS. Yields will be a bit lower (closer to single ended 1k HPS) but it would be much more manageable and you'll grow way better quality bud. I think you can use a 630w DE CMH bulb in the AC/DE hood from sunsystems too, so you can aircool it no problem. Plus you will actually be able to see your plants instead of having that putrid orange glow.

If you want to use 1000k DEHPS and you only have 8 or less feet of height, you'll be waaaaaaaaay better off using a 750w samsung/bridgelux strip light or QBs. Hell, you'd be better off with 750w of LED regardless.

 

[Flagg420]

I like my HPS buds... Im not willing to drop a couple grand to build my own custom LED setup, which is the ONLY way to get decent harvests from LEDs (coming from HPS... im sure CFL growers think its amazing)

I have moved my 2 600w MH's over to 315CMH's and am loving it, but im thinking more along the lines of 3x1k than the 5x315s.... just cant argue with them buds...

Still working it out tho, the cost savings of the CMH system would be well worth it...

You thinking double ended CMH, or dual bulb CMH?

 

[skoomd]

I like my HPS buds... Im not willing to drop a couple grand to build my own custom LED setup, which is the ONLY way to get decent harvests from LEDs (coming from HPS... im sure CFL growers think its amazing)

I have moved my 2 600w MH's over to 315CMH's and am loving it, but im thinking more along the lines of 3x1k than the 5x315s.... just cant argue with them buds...

Still working it out tho, the cost savings of the CMH system would be well worth it...

You thinking double ended CMH, or dual bulb CMH?

You could do a 750w samsung f series build for about $700-800 all said and done, including shipping. And it will 100% replace a 1000w DEHPS in yields, grow better quality bud, and use considerably less electricty/generate less heat.

I also built an overkill 320w f series strip LED build for my 3x3 tent that completely replaces a 600w HPS (or equal about 450-500w of CMH) for $400.

I would take 3x 1000w HPS setups over 5x 315w CMH setups any day though. 5x 315w CMH lights will only equal about 2x 1000w HPS setups in yield. Unless you meant 1000w DE CMH though...

Double ended CMH (630w-1000w) is much better than a dual bulb 630w CMH for a few reasons. 2 arc tubes in 1 hood doesnt perform as well as if they each had their own hood due to thermal reasons and having worse spread of light. And secondly DE CMH is quite a bit more efficient than single ended cmh. A normal 315w philips CMH bulb is 105 lumens/w or 1.9 umol/joule whereas a double ended 1000w CMH bulb is 130 lumens/w or around 2.3 umol/joule. NOTE THOUGH that a 360 degree light source like CMH looses about 20% of it's raw photon output from reflection losses in the hood, so 2.3 umol/joule might turn into 1.9 umol/joule by the time it leaves the fixture. LED would be closer to 2.5 umol/joule though and doesn't suffer such losses.

DIY LED with the samsung f series strips is $1 per watt or even less than that usually.

 

[Flagg420]

I am currently running 2x 1000w, with a 315 supplementing in the middle.... so its a matter of swapping the 315 for a 1k (I have the bulb and ballast already, so no additional cost to set up) Or replacing the 1k's with something more heat/electricity efficient.

I would like to throw on 3k, and put the portable AC in to keep it cool, but... the wife and the power bill have more sway than me on this one i fear...

 

[Flagg420]

How do the DE CMH compare with DE HPS as far as required height? I run approx 8ft ceilings, so DE HPS is out... I have pretty much no knowledge on the DE CMH builds... might be a legit option if I have the height to not cook my plants...

 

[skoomd]

How do the DE CMH compare with DE HPS as far as required height? I run approx 8ft ceilings, so DE HPS is out... I have pretty much no knowledge on the DE CMH builds... might be a legit option if I have the height to not cook my plants...

It's not bad for height with decmh. My friend runs a 630w de cmh in a 4x4' and keeps it 24" high. The 1000w decmh would need a good 30-36" tho

 

[Logan Burke]

I am looking into a replacement for my 1k watt HPS light as it is summer here and even with an 8 inch inline fan and an AC unit Im still having heat problems. I'm curious about the DECMH as well, because I only have about 7 or so feet of height, which is quite limiting. I will likely supplement with cobs and slowly add onto it as I save up, but in the mean time I need another primary light source. For a 6.5ftx6.5ftx6.5-7ft tent, do you guys have any suggestions?..I was thinking about two of the dual bulb, 630w cmh lights in my tent. Or, I could try a combo with my 1kw hps. Any tips would be sooo greatly appreciated

 

[xPeaceofMindx717]

Just Picked up a knockoff SunSystem 315 watt with a Philips bulb for $250+theft w/ free shipping on Amazon. As far as quality on the fixture/ballast, time will tell. I definitely don't think it would stack up to a 1000 watter, but thats not why i bought it. I look at this lamp as a low heat/power consumption alternative to a 400 watt digital HID system. I was having enough trouble keeping my tent cool with COB's, let alone switching out to HPS. That would have entailed an entirely new and larger exhaust system as well, pushing the price of those "affordable" HPS/MH systems, about equal to or exceeding an investment in a quality name brand CMH light. The low frequency ballast is another plus because I know I wont be messing with WiFi and Cell signals.

 

[hybridcheef]

Get yourself 1000watt double ended and don't get fooled by marketing. There's a reason big companies use just that, sometimes supplemented by 300watt plasma's. Cmh gives you airy buds and led still doesn't yield like hps.

you must be living in dinosaur years, cxb3590's and vero29's pull way more grams per watt then hps does lol. no blurple leds here, and the u mols are just as high!

 

[SunPlix CMH]

Well I was talking to the owner of a local hydro store about switching from two 1000 watt lights to four 600 watt lights and he started pointing at these Phantom CMH ballasts saying they will outperform 600's and they use a full spectrum bulb and better light that the plants need. Being as he is the owner I am skeptical of his claims cause i have not really heard of these not finding much definitive info on any search.

You should switch from HPS to CMH, full spectrum, less power bill, less heat, better quality, higher THD, etc.
All these are grown under CMH: https://www.instagram.com/sunplix_cmh/
A Facebook group discussing CMH: https://www.facebook.com/groups/248519675519386/
All kinds of CMH fixtures: https://www.sunplix.com/product-category/fixtures/

 

[Logan Burke]

Of course a 315w isn't going to stack up to a 1000w...its likely that even a 630w would fall just short of raw output. The big advantage comes in regards of quality and power usage...reduced electricity use from the lights themselves and cooling (Such as AC), as well as much longer life span bulbs in long term use is why it is financially a better option aside from the initial investment, which does cost more.

 

[Tas devil]

Hi gents.building a sealed room as i speak,using 16mm malamine.my mate wants me to go the 1000w hps in an 5x5 grow 7.1 ceiling ,but im keen to know if an 630 de cmh and a 315 cmh in there would b better,i know frockall on subject mate knows quite alot.i read a little abit on cmh better spectrum ,run more efficiently.cheaper to run,run cooler etc etc it will b my first grow going hydro with my friend helping.he states going his way will yield 22oz every 6 weeks.not including seedling and veg stage of course that will b on other side of the wall 870cm x1.5m room..im quite a few months off purchasing lights etc and thought id run it past you guys before i do..cheers

 

[SunPlix CMH]

Hi gents.building a sealed room as i speak,using 16mm malamine.my mate wants me to go the 1000w hps in an 5x5 grow 7.1 ceiling ,but im keen to know if an 630 de cmh and a 315 cmh in there would b better,i know frockall on subject mate knows quite alot.i read a little abit on cmh better spectrum ,run more efficiently.cheaper to run,run cooler etc etc it will b my first grow going hydro with my friend helping.he states going his way will yield 22oz every 6 weeks.not including seedling and veg stage of course that will b on other side of the wall 870cm x1.5m room..im quite a few months off purchasing lights etc and thought id run it past you guys before i do..cheers
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3 315s can give you more even light spread than 1 630DE and 1 315.
https://www.sunplix.com/product/315w-cmh-grow-light-fixture/
https://www.sunplix.com/product/400w-knob-dimming-low-frequency-cmh-grow-light-fixture/