315 cmh vs led

Norml56 said:

A lot of people are able to hit 1gpw with a 1k HPS so if you can hit 900 with LED you lost out on 100 grams. You saved a few pennies on electrical but I'd rather have the 3.5 ounces.

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But you were just previously talking about saving money on bulbs vs LED fixtures. Now you'd rather have the 3 ounces of weed.

If you're measuring this on the monetary value of the ounces of weed, then why is the initial cost of the more efficient LED even an issue in the first place?

Norml56 said:

If you are going with the route that Duke is with an almost 1:1 replacement in wattage it makes sense that he would be seeing better yields, but also defeats the main purpose of switching to LED which is reduced heat - reduced electrical cost.

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The main purpose of switching to LED was the increase in yield and efficiency.
You can't make an arbitrary judgement on what is the most important thing. It varies grower to grower

What's more important to you, to "save money on electricity" or to "have 3 ounces more weed" ?

If I swap my hps for LED and go from yielding a reasonable 0.7 gpw with a 400w HPS, to yielding 1.5 GPW with LED, I've doubled the yield potential of my space. That'll swing it for most growers.

Norml56 said:

I think this where I get confused or leary about using GPW as a good measurement. It's hard to believe people when they talk about GPW, but if I was hitting 1 GPW with my 315 and then swapped it out with half the wattage of LED I would need to hit 2 gpw to have an equal return. I don't see many folks saying they are hitting 2 gpw with LED, usually around 1.5 which would mean a 79gram reduction in yield.

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You're making a lot of weak arguments for LED, then knocking them down. Come on mate, think about what you're saying.

Why have you used those figures? Why half the wattage?

Why not just replace the 300w of CMH with 300w of LED and yield yourself 50% more (using your numbers)

Any particular reason?

At 1700umol, the Gavita 1700e is a 1:1 direct Replacement for a 1000w Hortilux/1600 umol in a 4 x 4 area at 18 inches, and is 645w.

The CMH does not go down to 285nm, and does not activate the UVR8 285nm protein receptor vs the Solacure. UV from the CMH is minimal at best. I run my Solacure at 40w. 2 of them with either a 1700e Gavita, or 1000w Hortilux HPS in a 4 x 4 for 6 hours. Use 3 with a 1150w DE Gavita in a 6 x 4 I start my seedlings with Gavita 1700e, and 2 Sola cure bulbs. Tried the 1000w Nanolux DE CMH 2 years ago, and it didnt do as well as a DE Gavita Pro. Gavita has huge IR, and some UV. Gavita Infrared will burn you skin if around it long enough.

Also the Gavita 1700e EQUALS the 1000w HPS/Hortilux. Does not outperform it. It does watt wise, but not production. Even Gavita says is a Direct Replacement. Does not claim to out perform it, though it does have 100 more umol. But their claim is direct replacement in a 4 x 4 area.

One must have the best Samsung, and Osram Diodes to get these numbers. Other companies equal, or better the Gavita 1700e, but still use Samsung/Osram diodes.

a 1000w Hortilux HPS bulb can be had for $60-$70usd. I replace them every 2 flowering cycles, and every 90 days veg at 24 hours.

I replace the DE Gavita every year of 24 hours on. They claim 90% efficiency at 10,000 hours. I still swap them out. Also replace the hood every year. Every bulb swap

a mongo frog said:

There is one gigantic measurement that a lot of people look at for success. Guess what it could be.

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4” is average

bk78 said:

4” is average

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In the USA its 6"and for some reason i sit at 3" hard, but its super thick. It looks like a tuna can. Ill post pic one day.

a mongo frog said:

In the USA its 6"and for some reason i sit at 3" hard, but its super thick. It looks like a tuna can. Ill post pic one day.

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Wrong

Norml56 said:

I think this where I get confused or leary about using GPW as a good measurement. It's hard to believe people when they talk about GPW, but if I was hitting 1 GPW with my 315 and then swapped it out with half the wattage of LED I would need to hit 2 gpw to have an equal return. I don't see many folks saying they are hitting 2 gpw with LED, usually around 1.5 which would mean a 79gram reduction in yield. If you are going with the route that Duke is with an almost 1:1 replacement in wattage it makes sense that he would be seeing better yields, but also defeats the main purpose of switching to LED which is reduced heat - reduced electrical cost.
I know a lot of people on this forum don't like Hybridway or the way he conducts his side by sides, but after his side by side with CMH and I believe it was the diablo boards from HLG the CMH won far as yield goes.

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i think if your enviroment fits for a LED setup and youre not dependend on the radiant heat of a CMH you will get your 2 GPW with Leds as youre a good grower.
its not really hard to reach the 2GPW in a tent with modern leds like the LM301H or similar.
eifficacy creeping up every year for LEDs.
most people i know would have problems using a recent LED at 315W in a 3x3, myself included, thats too much PPFD to handle without CO2.

daFreak said he easily have 1.5 GPW with COBS and consider that more modern mid power leds are giving even more usable light as the efficacy is higher and they can be used closer to the canopy with less reflection losses.
also as far i could read 1-2pound (450-900g) is considered to be a good yield for a 1000W HPS.
so he is just in line with his 900g a 600W COBs i would say.

the point is buying a, ppfd output wise comparable, led fixture isnt more expensive then buying a CMH nowadays.
if a cheap CMH fixture is about 200$, only inlcuding a no name ballast and a cheap bulb i guess.
its maybe fairer to compare them to the generic 240W meanwell driver lm301b fixtures on amazon who are similar priced at below/about 200$ stating even 3y waranty (not a huge fan of these fixtures but theyre halfway comparable to cheap CMH offerings would say).

these 240W x 2.6ppfd cheap led fixture should give you about 624ppfd.
a 315W CMH give you 598ppfd minus the way bigger reflector losses 15%, extra hanging height needed, etc.

if you have cheap electricity like to grow with CMH and have your enviroment dialed in around it, nothing wrong to go that route.
just the price comparsion doesnt work and yes 2 GPW is doable with LEDs.

JoeBlow5823 said:

Nope. Read what i quoted. 100 led watts = to 250 hps watts. Bullshit.

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Hmm I think maybe your not using leds joe. I have been using Mars hydro tsl 2000’s (3 of them) in a 5 by 8 space with two Mars tl 1000’s and I’m getting very nice results. With no HID’s or “uv” supplemental light. And as always, pics to prove it or it’s not true!

cobshopgrow said:

i think if your enviroment fits for a LED setup and youre not dependend on the radiant heat of a CMH you will get your 2 GPW with Leds as youre a good grower.
its not really hard to reach the 2GPW in a tent with modern leds like the LM301H or similar.
eifficacy creeping up every year for LEDs.
most people i know would have problems using a recent LED at 315W in a 3x3, myself included, thats too much PPFD to handle without CO2.

daFreak said he easily have 1.5 GPW with COBS and consider that more modern mid power leds are giving even more usable light as the efficacy is higher and they can be used closer to the canopy with less reflection losses.
also as far i could read 1-2pound (450-900g) is considered to be a good yield for a 1000W HPS.

yield of 1000w hps?

hello everyone! i was just wondering about how much i will yield off 16 plants under a 1000w hps? i just recently bought one and i'm curious

www.rollitup.org

so he is just in line with his 900g a 600W COBs i would say.

the point is buying a, ppfd output wise comparable, led fixture isnt more expensive then buying a CMH nowadays.
if a cheap CMH fixture is about 200$, only inlcuding a no name ballast and a cheap bulb i guess.
its maybe fairer to compare them to the generic 240W meanwell driver lm301b fixtures on amazon who are similar priced at below/about 200$ stating even 3y waranty (not a huge fan of these fixtures but theyre halfway comparable to cheap CMH offerings would say).

these 240W x 2.6ppfd cheap led fixture should give you about 624ppfd.
a 315W CMH give you 598ppfd minus the way bigger reflector losses 15%, extra hanging height needed, etc.

if you have cheap electricity like to grow with CMH and have your enviroment dialed in around it, nothing wrong to go that route.
just the price comparsion doesnt work and yes 2 GPW is doable with LEDs.

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The problem with your argument is it's too much to do with logic, numbers, and what most growers would regard as basic common sense.

People pin their mast to a flag and it doesn't really have to do anymore with the logic of it.
From our perspective, having made the switch, there's no looking back. I'm sure if the people making arguments against it used one of these fixtures and dialled it in, there'd be no more debate with that individual. This is more about being open minded than it is the technology.

The majority of them are missing out on yield, I'm sure about that. That's their choice I suppose and if it's backed up by the notion that other bulbs produce superior weed, that's just another obstacle in their way of making what to me and most people nowadays is the obvious choice.

GrownAtHighAltitude said:

The UV output is the 315's secret weapon that LED can't match.

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But what does it do, and how does that translate into your grow?

a mongo frog said:

In the USA its 6"and for some reason i sit at 3" hard, but its super thick. It looks like a tuna can. Ill post pic one day.

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Well as they say, long and thin goes too far in, but short and thick does the trick.

Norml56 said:

That's really what I'm talking about. Most people replace a 1000 watt HPS with around 600watts of LED or at least that's what I'm told will replace it. I'm still skeptical about that number. A lot of people are able to hit 1gpw with a 1k HPS so if you can hit 900 with LED you lost out on 100 grams. You saved a few pennies on electrical but I'd rather have the 3.5 ounces. From what I can tell to truly increase your yield you need to do a 1:1 replacement. I would bet that 99% of the people using LED are in the same situation as you with height/sq ft restrictions because of tents.

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To be honest I have no idea what you are talking about. Other than saying you are skeptical of mine and other's numbers to which I say you're a douche and used to talking shit on the net. If you want that other 3.5 oz then take that wattage you saved then add another LED and get a lot more, or.....do what I said and add more plant numbers.

And if anybody should be skeptical here it should be us about you claiming that a lot of people are getting 1gpw with HPS and the kind of setup I'm talking about, 4 plants in a tent with 3 weeks veg. I'd bet you've never hit it, and lets put it this way, anything you say at this point I'm going to be skeptical of.

DukeFluke said:

But what does it do, and how does that translate into your grow?

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More trichomes, more sticky icky.

I use SolarCures also but I probably don't need them.

I have no idea why people keep coming here to argue about how much better high end LED fixtures are when this thread is specifically about 315 CMH. A 315 CMH will give you a better yield and better quality than a similarly priced, pre built LED, that's a fact. 315 CMHs are nice because they really hit a sweet spot for price and quality of bud in a small tent. OF COURSE you could spend more money for an LED that blows it out of the water, no one is disputing that. But to say that LEDs are better in EVERY situation and for EVERY budget is simply wrong. A 600 watt hps for $129 is still the best choice for anyone on a budget that wants to grow in a bigger tent-to beat that you'd need to spend 4-5 times that for a pre-built LED that would compare. Most people that come here to learn how to grow will give up on it sooner rather than later, so an HPS light is a better option for new growers who are unsure about their long term growing career. We're in a pandemic people, why needlessly waste your TP money?

At the higher end, looking at LEDs vs 1000 watt DE fixtures, I'm still not convinced they are worth switching to IN EVERY CIRCUMSTANCE. Sure, if you have high electricity prices and you are factoring it the initial price which is almost 5 times more than a DE fixture, you will eventually come out on top, esp due to reduced cooling costs during the summer-but this is entirely situational. Some people rely on their DE fixtures for heat during the winter, so it becomes a little more complicated in those situations. In terms of pure yield, LEDs beat HPS handily on a watt to watt basis, but as someone else here said, most LED fixtures being compared to a 1000 watt DE are in the 600 watt range-are they getting DOUBLE the yields? I honestly don't know. I've looked at most of the 1000 DE vs LED comparison threads and I don't see any that really convince me either way. And what about 1000 DE CMH? I can't seem to find much on those.

I think the rabid LED supporters here think people are arguing with them, when in fact, most are agreeing with them. They just have a hard time admitting that LEDs might not be right for EVERYONE and for every situation. Budget matters for a lot of people.

GrownAtHighAltitude said:

More trichomes, more sticky icky.

I use SolarCures also but I probably don't need them.

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I've noticed no difference between the 315s and these LED I'm using now in terms of trichome production. Maybe in the early stages of using them people are struggling to get their plants as healthy as they were under HID bulbs and as a result it's turning out inferior looking bud. Far as I can see there's no evidence to support this idea. To me, if it's not just another weed myth, it's massively overestimated

DukeFluke said:

I've noticed no difference between the 315s and these LED I'm using now in terms of trichome production. Maybe in the early stages of using them people are struggling to get their plants as healthy as they were under HID bulbs and as a result it's turning out inferior looking bud. Far as I can see there's no evidence to support this idea. To me, if it's not just another weed myth, it's massively overestimated

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I noticed a huge difference between the 400watt HPS, 400watt CMH Retrofit, and 315 CMH's. 315's win hands down.

I only use LEDs in veg so far but of course lots of people are having good luck with them in flower. I just didn't feel like spending $2000+ to light my room when it only cost me $1000 with CMH. Also, I live in a very cold climate and LED doesn't put out enough heat. I'd end up spending more than I already do to get leaf temps up.

It was a no brainer for me but everyone has their own direction, for sure. The electricity costs end up being about the same and the lamp replacement costs are really the only other expense to consider.

When prices eventually bottom out, just like it has done with all previous lighting technologies I've witnessed in the 20+ years I've been following this stuff, I might switch out once actual diode and ballast longevity is proven.

Rurumo said:

I have no idea why people keep coming here to argue about how much better high end LED fixtures are when this thread is specifically about 315 CMH.

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Are you in the wrong thread?

This thread is titled "315cmh vs LED"

And the OP asks "Should I change all my 315cmh bulbs or go all LED"

So there's a debate about which one is better why. I've already conceded that if you're on a shoestring then you should get a cheap HPS and be done with it. CMH is then just as comparatively expensive compared to a budget hps kit as Led is to CMH.

If it's all about the money money money, then get the cheapest shit you can find and get a fucking grow on. Otherwise you can come here and find the different opinions on which one is best and why.

Rurumo said:

A 315 CMH will give you a better yield and better quality than a similarly priced, pre built LED, that's a fact.

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No it's not. Unless your definition of "similar" is different from mine. And why are you narrowing it down to pre built? Should we have all the options?

I came here initially looking for advise on the spider farmer. Then people steered me onto Alibaba... and then onto building. I wouldn't have even thought to do it but in the end, that's where I went with it and built my own with Bridgelux Eb gen 3 strips.

People should have all the options and all the opinions when asking a question like this, not be herded into single lines which point to there being a clear answer. The truth is there is not.

A CMH kit where I shop is about £260
I think I built my 320w fixtures for almost exactly the same price. Maybe I spent £50 more

I've said this before and I mean it, my bridgelux Led shits on the CMH. There's no comparison between the results. The footprint is better, the buds are solid all down the plant right into the corners of a space which 315w of cmh just cannot light efficiently.

And that is a fact

Rurumo said:

But to say that LEDs are better in EVERY situation and for EVERY budget is simply wrong.

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Who said it. and where?

If Budget is the key, like I say, spend less and get the essential kit. All of this is moot then because CMH is not that, it's an upgrade from bog standard basic.

And there are too many people out there killing it with Kingbrites for them to be dismissed as an option for people wanting to do 300w of Led on a CMH-type budget.

GrownAtHighAltitude said:

I noticed a huge difference between the 400watt HPS, 400watt CMH Retrofit, and 315 CMH's. 315's win hands down.

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Ah but that's comparing hps to cmh. Maybe there's some difference maybe not, but I'm not seeing many pictures to convince me, in fact I've seen none. On the whole internet. I hear what you're saying about budget and that's all personal choice. But If the CMH trichome thing was real there'd be more evidence to back it up.

Any pictures yourself?

315 CMHs on left, 400W CMH retrofit on the right. Look at the pattern of white light against the wall. You can see the waveform of the magnetic ballasts affecting the light output, captured in the photo. I don't have any bud pics from the 400 because I wasn't taking photos for years but I've noticed a difference since switching to all 315's. We can drop the 400w HPS argument but I think we all know what the light output looks like from those.





I haven't taken pics in a few weeks but this was at 44 days w/315's, and it's a fricken Barneys Farm strain:



Wish I had some older grow pics to compare to. This is definitely an improved room too, so many variables changing and I can't say for certainty what helps the most. I just know I like the light output very much. This is the first real grow in this room also so many areas for improvement. It would be nice if Spring would come.

I also like my T5 retrofit LED bulbs too though, and I know people get great results with LED in flower also. I hope to try them out some day.

Day 58 Bogglegum



Day 58 White Widow (Phoenix Seeds)

GrownAtHighAltitude said:

More trichomes, more sticky icky.

I use SolarCures also but I probably don't need them.

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CMH doesn't put out as much UV as most would like to believe. Your Solacures are doing the heavy lifting there. If there's any part of the spectrum that CMH beats LED in, it's IR output. Huge IR spike from CMH lamps around 820nm, but not too much below 380nm really.

I've grown very frosty nugs with LED alone, although I do have Agromax PureUV which I sometimes use.

This was grown with LED only, does anyone think it's lacking in tricombs?..