Input needed for experiment comparing COB LED to HPS DE

Should the HPS plants veg under LED then transfer to the HPS tent?

  • Yes

    Votes: 4 36.4%

  • No

    Votes: 7 63.6%
  • Total voters
    11
CCCmints

CCCmints

Well-Known Member
I'm purchasing a lux meter to observe the CXB3590 (CD) 3500K & Vero SE 29 Gen 7 (D) 3500K @ 1.75 amps. The results of this observation will be used for a 12 COB fixture design. I'll likely test more COBs, and these same COBs, at different currents after these two have been tested @ 1.75a. Any other COBs you'd like to suggest for testing I'll consider purchasing as well.

For now these will be my options:
[CXB3590] 36 x 1.75 = 63 Watts || 756 Watt Fixture
[Vero 29] 36.6 x 1.75 = 64.05 Watts || 768.6 Watt Fixture

Once I've built my fixture, I want to run, document, and present a proper experiment comparing COB LED to 1000w HPS DE, with LED running @ 20-25% less power draw. The problem is, even the HPS guys agree HPS is not ideal for vegetative growth. I don't want to appear bias towards LED by using HPS for veg. After all, the big question we all have right now is; Can LED hang with HPS during the flowering stage?

I'd love some input on this while I wait for the lux meter, COBs, and driver to come in. I can't grow cannabis right now, so I'm looking for a plant which has similar growth characteristics to marijuana. I'm considering Sunn Hemp, Electric Daisy, Spider flowers, Cranberry Hibiscus, etc.

Here's a link to the page I got these ideas from:
https://www.greenrushdaily.com/legal-plants-similar-cannabis/

For the experiment, since I'm choosing to test LED with a kelvin temp suitable to full-cycle growth, should I veg the HPS plants alongside the LED plants in the same tent during veg and then transfer the HPS plants to their own tent under the 1000w HPS DE light for flowering once its time to switch the photoperiod to 12/12?
 
Last edited:
rkymtnman

rkymtnman

Well-Known Member
CCCmints said:
For the experiment, since I'm choosing to test LED with a kelvin temp suitable to full-cycle growth, should I veg the HPS plants alongside the LED plants in the same tent during veg and then transfer the HPS plants to their own tent under the 1000w HPS DE light for flowering once its time to switch the photoperiod to 12/12?
Click to expand...
yes.
unless your cobs are gonna be 2100K or close, it won't be fair vs HPS in veg.
 
ANC

ANC

Well-Known Member
These are DIY, HLG 240-54A with three 22s to a driver, we adjust output as the clones mature, we use the same COBs (just less of them) from right after clones root till flower.
 
CCCmints

CCCmints

Well-Known Member
ANC said:
These are DIY, HLG 240-54A with three 22s to a driver, we adjust output as the clones mature, we use the same COBs (just less of them) from right after clones root till flower.
Click to expand...
Adjust output meaning you dim the fixtures or you're actually using less COBs at certain points in the grow? Also, its been brought to my attention the forward voltage of the COB changes depending on how you drive them. Do you know anything about this?
 
ANC

ANC

Well-Known Member
We use fewer banks when the plants are small as they take up less floor space.
As they grow and get bagged up we add more banks, once we flip we start dialing up output incrementally every week. We use the drivers with current and voltage adjustable, although V has to stay maxed. It is a good setup and will keep running even if one of the 3 COBs crap out,
 
CCCmints

CCCmints

Well-Known Member
ANC said:
We use fewer banks when the plants are small as they take up less floor space.
As they grow and get bagged up we add more banks, once we flip we start dialing up output incrementally every week. We use the drivers with current and voltage adjustable, although V has to stay maxed. It is a good setup and will keep running even if one of the 3 COBs crap out,
Click to expand...
Ok I see what you're doing. I didn't know there were drivers where you could adjust the output current. I thought if I wanted to test something @ 2.1a, I'd need a 2.1a driver and if I wanted to test at 1.7a then I'd need a 1.7a driver. Is there a driver I could use to test different currents without needing to buy a driver for the specific current I want to test? Also, what have you found to be best regarding dimming during veg? I'm sure you go 100% at flower, but for veg? I know the typical, "50% during veg, 100% during flower" is likely not the best practice.
 
ANC

ANC

Well-Known Member
Just look at the HLG datasheets They list the component numbers for the adjustable units.
They have 2 potentiometers on.

We use a combination of low current and adjusting the distance between the canopy and banks.

We step up the power until we are at full power in the last week of flower. We run 54 days from flip to cut.
 
CCCmints

CCCmints

Well-Known Member
ANC said:
Just look at the HLG datasheets They list the component numbers for the adjustable units.
They have 2 potentiometers on.

We use a combination of low current and adjusting the distance between the canopy and banks.

We step up the power until we are at full power in the last week of flower. We run 54 days from flip to cut.
Click to expand...
I'm confused. I'm not talking about dimming the light, but adjusting the output current of the driver so I don't need to buy a separate driver for each amperage I want to test. When I view the datasheets I see things like the following:

ELG-100-C700 (0.7a)
ELG-100-C1050 (1.050a)
ELG-100-C1400 (1.4a)

I don't see any drivers with adjustable output currents. I'm aware you can use potentiometers to dim the lights, but I'm saying I think I need to purchase separate drivers if I want to test a COB @ 1.4a AND 1.7a.

If this isn't true, you're a Godsend. Could I trouble you to post a link to a driver with adjustable output current? Sorry I'm stoned I can't seem to find any.
 
CobKits

CobKits

Well-Known Member
CCCmints said:
I'm purchasing a lux meter to observe the CXB3590 (CD) 3500K & Vero SE 29 Gen 7 (D) 3500K @ 1.75 amps. The results of this observation will be used for a 12 COB fixture design.
Click to expand...
youre not going to see much difference there. veros are cheaper and should have equal if not slightly greater output at a given wattage. side by side at a fixed current will bias your data as the chips operate at slightly different voltages. i dont want to discourage experimentation but in some cases its better to draw on the body of knowledge as opposed to reinventing the wheel, esp when yo uhave to spend money on extra chips to experiment

CCCmints said:
I'm confused. I'm not talking about dimming the light, but adjusting the output current of the driver so I don't need to buy a separate driver for each amperage I want to test. When I view the datasheets I see things like the following:

ELG-100-C700 (0.7a)
ELG-100-C1050 (1.050a)
ELG-100-C1400 (1.4a)

I don't see any drivers with adjustable output currents. I'm aware you can use potentiometers to dim the lights, but I'm saying I think I need to purchase separate drivers if I want to test a COB @ 1.4a AND 1.7a.
Click to expand...
dimming *is* adjusting current. so your 1.4A driver can operate at either 1050 or 700 mA (but not with as many cobs in series as the drivers designed for the lower currents have higher voltages)
 
CobKits

CobKits

Well-Known Member
ANC said:
We use the drivers with current and voltage adjustable, although V has to stay maxed
Click to expand...
if youre using 54A with CXM22, id advise turning the voltage down to just over the max required. that way if you drop a cob youre not sending the rest of the cobs up to 60V which is what teh 54A can do when cranked all the way up

would operate exactly the same for you guys except offer that additional protection
 
CCCmints

CCCmints

Well-Known Member
CobKits said:
youre not going to see much difference there. veros are cheaper and should have equal if not slightly greater output at a given wattage. side by side at a fixed current will bias your data as the chips operate at slightly different voltages. i dont want to discourage experimentation but in some cases its better to draw on the body of knowledge as opposed to reinventing the wheel, esp when yo uhave to spend money on extra chips to experiment



dimming *is* adjusting current. so your 1.4A driver can operate at either 1050 or 700 mA (but not with as many cobs in series as the drivers designed for the lower currents have higher voltages)
Click to expand...
Oh, wow. So dimming the driver changes the output current, ok. Seems obvious, but I am fairly new to this. I'd prefer to not buy the CXB3590 as I have little faith in it performing well enough to make up for the price difference compared to other COBs. So all I need is a driver with dimming capabilities and a potentiometer to dim it to the amperage I want to test. How do I know, exactly, what amperage I'm running based on the amount I dim with a multi-turn potentiometer? Is it just, dim 1.75a @ 20% = 1.4a?

I think LED can compete with HPS @ 750 Watts LED vs. 1000 Watts HPS. So, ideally, I'd like to push the COB I choose @ 62.5 Watts/Diode. Maybe I'll just purchase the Vero 29 Gen 7 SE 3500K COB and test it at various currents until I come up with something I'd be willing to invest in.
 
nfhiggs

nfhiggs

Well-Known Member
CCCmints said:
I'm purchasing a lux meter to observe the CXB3590 (CD) 3500K & Vero SE 29 Gen 7 (D) 3500K @ 1.75 amps. The results of this observation will be used for a 12 COB fixture design. I'll likely test more COBs, and these same COBs, at different currents after these two have been tested @ 1.75a. Any other COBs you'd like to suggest for testing I'll consider purchasing as well.

For now these will be my options:
[CXB3590] 36 x 1.75 = 63 Watts || 756 Watt Fixture
[Vero 29] 36.6 x 1.75 = 64.05 Watts || 768.6 Watt Fixture

Once I've built my fixture, I want to run, document, and present a proper experiment comparing COB LED to 1000w HPS DE, with LED running @ 20-25% less power draw. The problem is, even the HPS guys agree HPS is not ideal for vegetative growth. I don't want to appear bias towards LED by using HPS for veg. After all, the big question we all have right now is; Can LED hang with HPS during the flowering stage?

I'd love some input on this while I wait for the lux meter, COBs, and driver to come in. I can't grow cannabis right now, so I'm looking for a plant which has similar growth characteristics to marijuana. I'm considering Sunn Hemp, Electric Daisy, Spider flowers, Cranberry Hibiscus, etc.

Here's a link to the page I got these ideas from:
https://www.greenrushdaily.com/legal-plants-similar-cannabis/

For the experiment, since I'm choosing to test LED with a kelvin temp suitable to full-cycle growth, should I veg the HPS plants alongside the LED plants in the same tent during veg and then transfer the HPS plants to their own tent under the 1000w HPS DE light for flowering once its time to switch the photoperiod to 12/12?
Click to expand...
Veg all of them with MH lights. Flower with the different combinations.
 
CCCmints

CCCmints

Well-Known Member
nfhiggs said:
Veg all of them with MH lights. Flower with the different combinations.
Click to expand...
I don't want to veg with MH lights simply because I want to compare LED during the flowering phase vs HPS. I'm trying to show a 750w LED fixture can outperform a 1000w HPS DE in flower, and since I want the experiment to be properly conducted, I want to veg with the same LED fixture then transfer those plants to the flowering tent under HPS.
nfhiggs said:
https://www.amazon.com/dp/B017FSED9I?th=1
Click to expand...
Thank-you for this. I'll definitely purchase that.
 
CobKits

CobKits

Well-Known Member
CCCmints said:
Oh, wow. So dimming the driver changes the output current, ok. Seems obvious, but I am fairly new to this.
Click to expand...
well technically if you have a voltage adjustable driver like meanwell "A" version, you can dim with voltage or current. if you look at any LED datasheet, remember it can ONLY operate on that curve (or thereabouts based on chip-to-chip voltage variations as well as temperature effects) . so limit voltage and it will operate at the corresponding current, limit current and it will operate at the corresponding voltage. that said all the meanwell B drivers limit current to control chip output, so 9 out of 10 people will think of current limiting when thinking of dimming.

CCCmints said:
I'd prefer to not buy the CXB3590 as I have little faith in it performing well enough to make up for the price difference compared to other COBs.
Click to expand...
they are great chips but they dont give you X% more of anything for the X% incremental cost. thats not to say you cant grow amazing plants with them, they are right there with most common chips and in just about every garden would be indistinguishable from other similar cobs but unfortunately are overpriced right now.

CCCmints said:
How do I know, exactly, what amperage I'm running based on the amount I dim with a multi-turn potentiometer? Is it just, dim 1.75a @ 20% = 1.4a?
Click to expand...
spending $30 on a decent multimeter would be indipensible and it can do everything you want

CCCmints said:
I think LED can compete with HPS @ 750 Watts LED vs. 1000 Watts HPS.
Click to expand...
i know it

CCCmints said:
So, ideally, I'd like to push the COB I choose @ 62.5 Watts/Diode.
Click to expand...
great spot for any of the chips you describe. hard to go wrong anywhere below 75W

CCCmints said:
Maybe I'll just purchase the Vero 29 Gen 7 SE 3500K COB and test it at various currents until I come up with something I'd be willing to invest in.
Click to expand...
vero B at the same price as D is a no brainer. if you splurge for C theres a good bump there as well. in the 50-70W range id rank the $17 luminus as the best value followed by the citis or the veros (about the same cost/benefit ratio).
 
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