CMH / QB288 / QB120 / SB240 / VERO 29C comparison...

[CobKits]

like... wtf are these numbers?

I haven't seen lm/w or µmol/J numbers that high anywhere else... what do those even mean? what am I looking at here?...

LER and QER dont tell you efficiency, they tell you about the spectrum

in other words IF that chip was 100% efficient (impossible- almost nothing we use in practice is outside of the lower 40s to upper 60s in efficiency) THEN it would have 321 lm/W and 4.86 umol/J

IF the chip is operated at 50% efficiency THEN it will have about 161 lm/W and 2.43 umol/J

 

[CobKits]

if I was rich, I'd do just that... unfortunately, I'm not.

for what youre spending on lights a $150 hydrofarm is a no brainer

ill go as far to say its absolutely essential if you are mixing differrent numbers, sizes, and styles of boards and cobs in the same space

 

[ganjamystic]

for what youre spending on lights a $150 hydrofarm is a no brainer

whatever I end up spending on lights will already be more than I can afford... so I'm going to hold of on a meter and just keep reading the plants for now.. I do want to get a meter as soon as possible though...

ill go as far to say its absolutely essential if you are mixing differrent numbers, sizes, and styles of boards and cobs in the same space

I''m actually not trying to mix boards and cobs or anything like that in the same space.. if you can, please read my post below. you are super helpful and if you read that post you'll be able to see what I'm going for...

I have a 7x7 space (four 3x3 squares, with 1 foot aisle space in between) that is due for an upgrade...

I built a few qb lights, which are currently lighting 1 quadrant of the space; the remaining 3/4 is lit by blurples ...

I'm ready to send the blurples on their way ... and upgrade the lighting to something more efficient (same amount of light for less W and with less heat, rather than more light for same amount of W and heat.. if that makes sense... I in other words, I don't need more light in the space, just less heat and a lower power bill).. ...

I've decided to move the three qb lights I built (each currently has 2 3500K qb288s on slate 3 triple heatsinks driven in parallel by HLG-320H-54A drivers) to 3 2x4 tents, giving me 24 sqft of extra space at up to 40W per sqft .. or move all 3 to a 4x4 and drive all 3 with only 2 of the drivers, giving me only 16 sqft of extra space at up to 40W per sqft but with more uniform coverage and greater efficiency...

which leaves me to light the 4 3x3 quadrants of the main space... I'd like to just go with 4 of the same thing, whatever I decide to do... here's all the possibilities I'm considering (in no particular order.. no preference yet, just trying to do a proper analysis before deciding):

• 2 x 1000w de hps (revolution micro deva, on light movers, dimmed to 60%)
• 4 x 315w cmh
• 8 x 260w qb288 kits (2 per 3x3, dimmed to ~157.5W each)
• 4 x 315w qb288 diy lights (just like the ones I already built, but with the better slate 2 heatsinks)
  
• 4 x 315w qb120 diy lights (each consisting of 6 qb120s, dimmed to ~52.5W each)
  
• 4 x 315w photonfantom diy lights (each consisting of 4 sun boards, fusion boards, or wavy boards at ~79W each)
• 4 x 400w timber 4vs (dimmed to ~315W each)

basically I want to keep the wattage constant (~315W per 3x3 quadrant) and analyze the PAR/$ of the various options, irrespective of other factors such as light uniformity, potential bulb changes, spectral differences, etc.... I just want to figure out the PAR/$ of all the possibilities I listed and I can then make my decision, taking all those other factors I mentioned into consideration.... if that makes sense...

 

[CobKits]

if i had a room with aisles i prob wouldnt even consider using a light source like boards or naked cobs that cast light wide. that said 1' is not very wide and any stray light prob goes right to the lower canopy of the next quadrant

at a fixed wattage, par will depend on how hard you drive any of those options. anyone can match any other if you use enough, you just need to use more an spend more money to achieve your target efficacy level (in your case measured by ppfd on canopy per watt of input power)

adding HPS into your mix is again another variable (spectrum)

id use 2x 315 cmh before i put a 1000 DE hps on a mover but thats just me.

all the info you need is on this page but im not going to crunch the individual numbers for you to find out which of the 5 phosphor white light rigs you proposed are slightly more efficient and at what cost

 

[ganjamystic]

if i had a room with aisles i prob wouldnt even consider using a light source like boards or naked cobs that cast light wide. that said 1' is not very wide and any stray light prob goes right to the lower canopy of the next quadrant

right. they're hardly aisles... by the time the plants fill in I can barely get through, but I can just barely if need be and that's the point. you are correct. all stray light just lights the lowers of the adjacent quadrants...

at a fixed wattage, par will depend on how hard you drive any of those options. anyone can match any other if you use enough, you just need to use more an spend more money to achieve your target efficacy level (in your case measured by ppfd on canopy per watt of input power)

I would drive all options just hard enough to achieve 315W in each 3x3..

• 2 x 1000w de hps (on light movers, dimmed to 60%)
• 4 x 315w cmh (100%)
  
• 8 x 260w qb288 kits (2 per 3x3, dimmed to ~157.5W each)
• 4 x 315w qb288 diy lights (100%)
• 4 x 315w qb120 diy lights (6 qb120s each, dimmed to ~52.5W each)
• 4 x 315w photonfantom diy lights (4 photon fantom boards at ~79W each)
• 4 x 400w timber 4vs (dimmed to ~315W each)

adding HPS into your mix is again another variable (spectrum).

I grew with hps for 7 years before going led, so I'm familiar with the spectrum.. it works!

id use 2x 315 cmh before i put a 1000 DE hps on a mover but thats just me.

from my (admittedly limited) understanding de hps is significantly more efficient than cmh... any reason in particular you'd choose the cmh?.. better spectrum in your opinion? you don't like light movers? the light movers would bring down the efficiency?... care to elaborate a little more on this?

all the info you need is on this page but im not going to crunch the individual numbers for you to find out which of the 5 phosphor white light rigs you proposed are slightly more efficient and at what cost

thank you for all your help. I realize this stuff probably seems easy to you by now (since it's your line of work and all), but for me and I'm sure a lot of other growers on here, this stuff is literally like a foreign language... and in my case, not like spanish which I took in highschool and sort of remember, more like chinese or japanese or something that doesn't even use the same letters...

I'm really trying my best to figure shit out myself, but I'd prefer help from the much more knowledgeable than myself peeps on here if anyone's willing..

 

[CobKits]

right. they're hardly aisles... by the time the plants fill in I can barely get through,

lol i imagined how darn sticky it is in there

I would drive all options just hard enough to achieve 315W in each 3x3..

• 2 x 1000w de hps (on light movers, dimmed to 60%)

dimming hps doesnt increase efficiency like leds (in fact it might even hurt it- just a guess but its for sure not helping it at *best* its same efficacy when dimmed)

as for the rest its irrelevant if you are running them at "100%" or "xx%" for each light source, as they all have different efficacies at different currents. outside of manufacturers oeprating limits"100%" is pretty irrelevant for specing leds as there is no standard. if one led/cob/board driven at "100%" was at all correlatable in efficacy to another running at "100%" you could use it. for your purposes its useless extraneous data

I grew with hps for 7 years before going led, so I'm familiar with the spectrum.. it works!

yes it does, 40 years behind it. we have better options now for efficacy and spectrum. for the time being hps is still tops in low capital cost. not sure that applies when you get into the boutique fixtures like the revolution series. just a guess they prob cost a lot more and only offer incremental performance increase over common DE fixtures

from my (admittedly limited) understanding de hps is significantly more efficient than cmh... any reason in particular you'd choose the cmh?.. better spectrum in your opinion?

yes better spectrum and coverage which imo more than makes up for the umols relative to hps

you don't like light movers?

loved em, used them since 97. gave up after losing 2 crops over the years to failing movers that parked over one end of the garden

led arrays eliminate the need for moving. moving is a compromise to compensate for the hotspots of large hid bulbs and are an unnecceasry addition/point of failure in the modern garden imo. in the end plants will take their DLI whether its incremental from a mover or constant lower light all day long. if efficient 150W-400W HPS bulbs were a thing 1000W hps and movers wouldnt be nearly as popular but again its a compromise.

thank you for all your help. I realize this stuff probably seems easy to you by now (since it's your line of work and all), but for me and I'm sure a lot of other growers on here, this stuff is literally like a foreign language... and in my case, not like spanish which I took in highschool and sort of remember, more like chinese or japanese or something that doesn't even use the same letters...

I'm really trying my best to figure shit out myself, but I'd prefer help from the much more knowledgeable than myself peeps on here if anyone's willing..

no worries, keep asking questions as fundamental understanding is important. in my mind you have a decision to make first

1.hps
2. cmh
3. led

IF you choose LED you can look at the other options, which tbh the difference between any of them will be minimal to your end results as compared to the difference in hps/cmh/led

overthinking isnt necessarily a bad thing, but it certainly is a thing

 

[ganjamystic]

ok cost analysis, just based on $ to cover each 3x3 quadrant with 315W of light, not taking PAR and other factors into account, starting with non diy options:

2 x 1000w de hps
- $445 x 2 (lights) + $175 x 2 (movers) = $1240

4 x 315w cmh
- $290 x 4 = $1160

8 x 260w qb288 kits
- $325 x 8 = $2600

4 x 400w timber 4vs
- $579 x 4 = $2316

 

[CobKits]

based in what you have told us about your budget, this is a no brainer.

4 x 315w cmh
- $290 x 4 = $1160

if you cant afford a $150 light meter spending twice the cost on gear to maybe squeak out 10% more bud per crop seems like a poor investment. not saying LED isnt superior but you gotta pay to play, nothings free

the CMH should do you well enough for a couple crops that a year from now coughing up cash for lights wont be so tough, and by then, LEDs will be both more efficient as well as cheaper

Alternatively if the led efficiency is what you want long term just buy LEDs and run them harder. you can certainly match that CMH with an $1100 cob rig, which you can cut the current in half to later and exceed the CMH performance. fairly easy to select cobs that can run at 150W all day long but are much more efficient at 75W

youre making false equivalencies by trying to compare ultra-efficient led rigs with CMH on a cost basis. you should be comparing LEDs run medium hard which will give same efficiency at similar cost to CMH and be a little more future proof (as well as not locking you in to bulb costs down the line)

 

[ganjamystic]

hold on one sec, you haven't seen the diy options yet...

 

[ganjamystic]

ok I haven't finished this yet, but look at the first option below..

diy options:

4 x 315w qb288 diy lights
- $72 x 8 (boards) + $57(?) x 4 (heatsinks) + $94 x 4 (drivers) = $1180 + cords, screws, connectors, wiring, etc.

4 x 315w qb120 diy lights
- $30 x 24 (boards) + drivers + frame + cords, screws, connectors, wiring, etc.

4 x 315w photonfantom diy lights
- $50 x 16 + drivers + frame + cords, screws, connectors, wiring, etc.

 

[CobKits]

assuming similar wattage per rig driver cost is nearly identical so just drop that from your analysis

 

[ganjamystic]

I'm saying this..

4 x 315w cmh
- $290 x 4 = $1160

4 x 315w qb288 diy lights
- $72 x 8 (boards) + $57(?) x 4 (heatsinks) + $94 x 4 (drivers) = $1180 ...

 

[CobKits]

sure as long as either one can be hung at appropriate height to uniformly illuminate

spend at least $30 on a cheap lux meter. i see no other factor that will influence your yield as much as proper uniform coverage

 

[ganjamystic]

yes better spectrum and coverage which imo more than makes up for the umols relative to hps

youre making false equivalencies by trying to compare ultra-efficient led rigs with CMH on a cost basis.

the funny thing is, from my perspective as a grower, spectrum really doesn't make all that much difference, assuming everything else is dialed... over the years, I've flowered with hps, blurple led, and now white led and I can say in my personal experience spectrum makes very little if any noticeable difference... If all other factors--environmental conditions, strain, medium, nutrients, water quality, etc.--are dialed, nearly identical buds of equally perfect quality can be produced under hps, blurple, or white led, assuming canopy light levels are the same... I haven't ever grown with cmh though...

sure as long as either one can be hung at appropriate height to uniformly illuminate

spend at least $30 on a cheap lux meter. i see no other factor that will influence your yield as much as proper uniform coverage

I've never owned a light meter to test exactly what PPFD it is that seems to be the sweet spot, I've just always gone by the brightness of the light reflecting off of the plants to my eyes as well as the plants reaction to it and the (apparent) uniformity of coverage.. and just dialed in the distance between light and plants that way... I've always eyeballed it basically...

I initially assumed it would require 4 qbs to evenly light a 3x3, but the spread of light from the boards is so wide, the coverage actually looks very even when I hang 2 qbs in line right in the middle... I guess I should get a lux meter and see how even it actually is

 

[ganjamystic]

If all other factors--environmental conditions, strain, medium, nutrients, water quality, etc.--are dialed, nearly identical buds of equally perfect quality can be produced under hps, blurple, or white led, assuming canopy light levels are the same... I haven't ever grown with cmh though...

ok I'll admit the buds I grow now are frostier than most I grew back in the hps days, but much of that has to do with having better genetics now and having just generally improved as a grower with time and experience.... I have friends who crush it with hps because they have good genetics and dialed environments and methods... my one friend, for example, grows the same forum cut gsc I do... his hps-grown buds, my blurple led-grown buds, and my qb-grown buds all look and smoke almost exactly the same!... for some odd reason, there's much more morphological variation in the buds from the mother vs the clones than there is between the clones flowered under different lights....

 

[Rider509]

Check out the HydroFarm PAR meter. I researched the hell out of PAR meters from Li-Cor and Apogee before I found a member here who had tested the HydroFarm meter against the pro meters at his college. He reported that the readings were very accurate. Super cheap. Horticulture Source has the best price right now.
I have no affiliation to either.

 

[Photon Flinger]

LER and QER dont tell you efficiency, they tell you about the spectrum

in other words IF that chip was 100% efficient (impossible- almost nothing we use in practice is outside of the lower 40s to upper 60s in efficiency) THEN it would have 321 lm/W and 4.86 umol/J

IF the chip is operated at 50% efficiency THEN it will have about 161 lm.W and 2.43 umol/J

I digress!!

Lumens is the result of the number of photons, wavelength (energy of photon) and a weighting factor skewed towards 507/550nm.

Quanta (QER) is just a raw photon count.

Major important point. We care about quanta for growing but lumens works well enough to guide us. Since we are not using the lights for the intended purpose of being able to see, we have to take the manufacturers published lumen performance, mingle it with the QER and same magic maths to come up with an approximate photon count in micromoles. Basically using one somewhat related performance measurement to obtain the value of another.

PAR meter skips the math and gives you the value at the measured point in the light space. Why they are so valuable for growing.

 

[ganjamystic]

I digress!!

Lumens is the result of the number of photons, wavelength (energy of photon) and a weighting factor skewed towards 507/550nm.

Quanta (QER) is just a raw photon count.

Major important point. We care about quanta for growing but lumens works well enough to guide us. Since we are not using the lights for the intended purpose of being able to see, we have to take the manufacturers published lumen performance, mingle it with the QER and same magic maths to come up with an approximate photon count in micromoles. Basically using one somewhat related performance measurement to obtain the value of another.

PAR meter skips the math and gives you the value at the measured point in the light space. Why they are so valuable for growing.

nice. I will def get a PAR meter eventually. in the meantime, I'll probably scoop one of the $30 lux meters and use some magic maths... https://www.apogeeinstruments.com/conversion-ppf-to-lux

 

[CobKits]

for coverage its kind of irrelevant. as you mentioned you watch the plants and have a good system. that+ any sort of measurement of light and you'lll be rockin

a good grower with a keen eye and any sort of rough metric will always top someone who can get an exact reading but neglects plant response

 

[Photon Flinger]

I read a bit more into the reasoning behind your request but I am still a little confused about some aspects. Agreeing with Cobkits that cmh would be best on the info available but maybe some out of the box thinking is possible.

What is the primary reason for the upgrade? Reduce costs? Replace failing equipment? Increase yields?

You already have blurples, since you are considering DiY, would upgrading those units be a possibility? Or even cost recovery selling them used to help with the budget?

Do you have to do this all at once or in stages? Staggering out your build 1 tent at a time is something to think about.

First things first, you should get the PAR meter. $150 investment for the best tool (besides plant themselves but plants are a bit slower) to dial in your lighting. Take that PAR meter and measure your current setup so you know what is working and have a baseline to compare with.