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CMH vs LED vs HPS

bigtacofarmer

Well-known member
Veteran
That's why you see high intensity in the uva/b regions with the 10k bulbs, having types of waves is the first thing, but the energy to drive them enough so they will reach the plant for the proper dose and effect is also key.
I think that's why CMH bulbs are giving good results, they mimick the sun best.
What lighting will you choose when hid is no longer available?
 

Cerathule

Well-known member
A lot if not most research will be done by PhD students with professors supervising spending their time trying to get funding. That shouldn't be a reason to discredit the work. Your other criticism is valid but I think the paper still answers the question "does UV do anything" with a rather reliable "yes".
Bro, I wouldn't be so critical but I've seen really manipulative industry-driven work (presumably payed) by the LED industry to acquire a bachelor sc.
What good is it when things are so faulty that the result is incredibly flawed?
But then they use that to promote fixtures that are twice the cost of others and have an inferior design that actually costs raw photon output...
 

snakedope

Active member
I have a question for the cmh pros too.
Do the double ended cmh give the same advantage as the de hps or is it just 2 bulbs in one lamp?
It's all about light output and spectrum
If you want to flower and veg big spaces and have more high yields then de hps is a no brainer
If profile expressions and spectrum testing and playing, high quality of resin in terms of individual substances and terepens not just amount (cuz hps will grow same amount of resin if not more) is more favorable then CMH would be a better option

The main thing I learned from LEDs is that in any given situation (unless you have 1 plant) it is better to divide light sources instead of making them more powerful, this only applies to HIDs because they start at a very high intensity threshold, you can divide them pretty much down to single 100w bulbs, or 3 x 250w bulbs, and get much better results if you had 1 de 750w at the same space.

This concept also works for LEDs in an unbeatable way, but dividing too much has a negative effect on intensity rates.

No, for example here HPS is superior taken all together
Light Quality Impacts Vertical Growth Rate, Phytochemical Yield and Cannabinoid Production Efficiency in Cannabis sativa
but these are not good LED specs. And HPS is the control. It's kinda funny when a single central bulb emittor is the control for many 4 COB arrays with 90° beam angle.

It's very easy to test actually also in your growtents, if you have different fixtures operating at a different beam-angle, you can adjust canopy PPFD to equal levels but then take another measurement at, say, +10cm, +20cm etc distance and you'll confirm that different lamps have a different level of "penetration" power.

The only way to do away with this is sinply using the same hardware constructs, just altering the colours, nothing else.
You still need to explain to us what's the point in all this spectrum research, if poor spectrum grows dank buds for years...
 

Cerathule

Well-known member
You still need to explain to us what's the point in all this spectrum research, if poor spectrum grows dank buds for years...
I shall reason up your bias?

I got my hands already full correcting your lack of knowledge, as seen here:
, this only applies to HIDs because they start at a very high intensity threshold, you can divide them pretty much down to single 100w bulbs, or 3 x 250w bulbs, and get much better results if you had 1 de 750w at the same space.

This concept also works for LEDs in an unbeatable way, but dividing too much has a negative effect on intensity rates.
it has zero to do with "your intensity" but that HIDs require a high operational temperature and thus, are more efficient with bigger bulbs (it has bulb specific limits so this is why 1000W HPS DE, 600W HPS SE, 315W CMH etc are some of the standards.). So there is no option to do it like LED do with bar lights, quantum boards, where higher LED count usually is a way to shows build quality and higher efficacy (less current per diode used).

Also, think about additional ballast and reflector costs for HIDs - yikes!

BTW you still need to show proof that you are actually a grower. Because, when you hit RIU about a few months ago, your very own words were that it is just a friend half an hour drive away that grows for you. And that you'd visit him over the weekend and then get some pics for us. They never came.
Back then your statements were so noobish you knew basically nothing about lights or growing.

There it started:

Now here you are presenting yourself as an old-fashioned grower with long experience and blablabla. Yeah, you've changed your story a number of times. And thought, just changing forums to eliminate the previous inconsistencies to create an old-school grower internet personality in search for folks to support your vague theories. :cautious:
 

snakedope

Active member
I shall reason up your bias?

I got my hands already full correcting your lack of knowledge, as seen here:

it has zero to do with "your intensity" but that HIDs require a high operational temperature and thus, are more efficient with bigger bulbs (it has bulb specific limits so this is why 1000W HPS DE, 600W HPS SE, 315W CMH etc are some of the standards.). So there is no option to do it like LED do with bar lights, quantum boards, where higher LED count usually is a way to shows build quality and higher efficacy (less current per diode used).

Also, think about additional ballast and reflector costs for HIDs - yikes!

BTW you still need to show proof that you are actually a grower. Because, when you hit RIU about a few months ago, your very own words were that it is just a friend half an hour drive away that grows for you. And that you'd visit him over the weekend and then get some pics for us. They never came.
Back then your statements were so noobish you knew basically nothing about lights or growing.

There it started:

Now here you are presenting yourself as an old-fashioned grower with long experience and blablabla. Yeah, you've changed your story a number of times. And thought, just changing forums to eliminate the previous inconsistencies to create an old-school grower internet personality in search for folks to support your vague theories. :cautious:
Nice bro, we always love your lack of knowledge when it comes to the real questions haha but keep writing on me I like being famous and all ;)
 

snakedope

Active member
i agree... if the conditions r rite, imo the best weed is grown outdoors...
I've had killer dope from hps for almost all my life, hps was the standard, outdoor was 2nd, and only if you took very good care of it and it was in a really sunny area it could match the hps buds, I believe the resin will be better quality all around if grown in good conditions outdoor.
Na thats not true. The de 750w has a way higher efficacy than the 250s. The 50s will make a more even coverage but will produce less light
I never claimed it will have higher output, I claimed it will be better to divide 750 to 3 x 250. Read before u post.
 

Crooked8

Well-known member
Mentor
ICMag Donor
Veteran
LEDs are great with :-

additional heating
additional UVB
additional UVA
additional far red
additional calcium

CMH/HPS are great straight out of the box
LEDs are great with :-

additional heating
additional UVB
additional UVA
additional far red
additional calcium

CMH/HPS are great straight out of the box.
Ive never needed to run heat, ever.
Never needed to supplement either uvb or uva
There are leds with more far red diodes than i prefer already in the fixture. They will photobleach a plant top just like hps.
The only reason people think they require more calcium is because they require more overall feed in general because you have a higher ppfd.

Higher ppfd requires higher feed.

Hps/cmh like any other light have a ton of requirements for success. Cant just plug it in out of the box. You need ac, you need air movement, you need environmental control. I feel this comment is very misleading.
 

Hammerhead

Disabled Farmer
ICMag Donor
Veteran
I have a question for the cmh pros too.
Do the double ended cmh give the same advantage as the de hps or is it just 2 bulbs in one lamp?

I used DE CMH 1st.. Then ALL changed to the PGZ base fixtures using 315/500w dual bulb fixtures. I loved the results from DE cmh. DE CMH has 2 ARC tubes in single bulbs. It is basically 2 bulbs in 1 package. I still have all of those fixtures/DE bulbs just in case.
 

exoticrobotic

Well-known member
Hps/cmh like any other light have a ton of requirements for success. Cant just plug it in out of the box. You need ac, you need air movement, you need environmental control. I feel this comment is very misleading.
Sure with HPS and CMH you need environmental control (not AC as i'm in the UK) but i find with HPS/CMH all you need is active extraction/passive intake which you obviously need irrespective of hps/cmh/led light type.

Sort that out and the rest runs itself without any issues which has not been my experience with leds.

All these extras with leds, different spectrums etc. Why is it necessary if there isnt anything missing in the first place? Is it just to satisfy our unnatural desire to 'improve' things. I dont think so.

You must have tried runs with HPS/CMH @Crooked8 as you've been a member here for 10 years.

Do you not notice any difference between the highs/plant demands under these different lights?
 
My old led grow. We called it "Frankenblurple". I had to swap T5s from 460nm to 6500k to 660nm to 730nm to 10000K to UVB, every grow. Fucking annoying. Thanks, capitalism. A closet full of T5 bulbs because you won't build a light that makes sense for at least another 20 years.
20230216_162304.jpg


If you aren't adjusting spectrum, you're growing "mids". There's no other way to put it. Full spectrum leds grow trash. I don't need to buy your sack to know it's garbage, just show me your lights.
 

Crooked8

Well-known member
Mentor
ICMag Donor
Veteran
Sure with HPS and CMH you need environmental control (not AC as i'm in the UK) but i find with HPS/CMH all you need is active extraction/passive intake which you obviously need irrespective of hps/cmh/led light type.

Sort that out and the rest runs itself without any issues which has not been my experience with leds.

All these extras with leds, different spectrums etc. Why is it necessary if there isnt anything missing in the first place? Is it just to satisfy our unnatural desire to 'improve' things. I dont think so.

You must have tried runs with HPS/CMH @Crooked8 as you've been a member here for 10 years.

Do you not notice any difference between the highs/plant demands under these different lights?
If you go back in this thread ive posted a lot of my experiences with all three types. Leds win in every category from my experience but it took getting used to.
 

Crooked8

Well-known member
Mentor
ICMag Donor
Veteran
My old led grow. We called it "Frankenblurple". I had to swap T5s from 460nm to 6500k to 660nm to 730nm to 10000K to UVB, every grow. Fucking annoying. Thanks, capitalism. A closet full of T5 bulbs because you won't build a light that makes sense for at least another 20 years.
View attachment 18811433

If you aren't adjusting spectrum, you're growing "mids". There's no other way to put it. Full spectrum leds grow trash. I don't need to buy your sack to know it's garbage, just show me your lights.
So you tried a shitty led and didnt do well and now hate on all leds. Nice.
 

Cactus Squatter

Well-known member
So just for all the people saying “led doesn’t grow good weed/LED somehow makes good weed grown under it suck poodle balls”…
I just started running some Haze crosses under LED that I’m currently finishing clones of under a CMH.
You’re gonna have to wait 15 or so weeks for the results but I have zero doubts the LED grown will be just as Fire if not more so than the CMH.

I’m confident enough in and happy enough with the LED results I’ve seen first hand that I plan on switching my CMH out to LED this summer.
 

exoticrobotic

Well-known member
but it took getting used to.
Please elaborate what took getting used to with leds?

This is my experience too with the mixed white spectrum leds which appear to my eye as more cool white in colour.

Constantly unhappy sick looking plants with rust spots, unnatural purpling, brown and yellow necrotic edges.

Plants showing enhanced purpling. These previously unseen extra anthocyanins a clear indication the plants are under stress. All ultimately translating to a plant that is less able to express its full and true potential with respect to terpenes and cannabinoids.

I have zero doubts the LED grown will be just as Fire if not more so than the CMH.

Wait 15 weeks and smoke it. It's great really :rolleyes:. I hope it still gets you high and you dont end up chain smoking chasing that missing hid buzz like i'm doing.

Dont get me wrong. led can grow large buds that get you high but if you have been smoking for 30 years and growing for that time you will discern a difference.

Where's the wow with led bud?

It's generally in the photo not the high...
 
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