Test room: DE HPS vs. Citizen COBs

I figured I would put this here instead of hiding it in the LED section. The room is normally a 4 DE HPS room with 2 4'x8' trays. The plants will get a couple days to get use to the lights and should be flowering by the weekend. I don't have a PAR meter, but do have a lux meter that I will use to set the fixture heights @ around week 2. It is to far away to check on every week.
Over the led tray is 12 COB's running a total of 1640 watts. They range from 4000k 70cri in one corner ( 2 COBs on one heat sink) and 3500k 80cri (6 on 3 heat sinks), and on the other end is the 3000k 90cri (4 on 2 heat sinks). The outer 2 fixtures are running each COB @ 125 watts each and the middle fixture is running each COB @ 160 watts. I am expecting this side to look like a staircase (4000k being the lowest)
Over the other tray, simply 2 DE HPS running on high. So, about 2600 watts. I will get this number verified ( I actually think it is higher).

Im going to tag along for this one, im in the process of doing the same so it will be good to see what happens what made you go from DE to Led?

@nevergoodenuf What's the size of the passive heatsinks?
Also do u have a link were to buy them?
cheers VG

This isn't my room. It belongs to a friend that is willing to help me get a better grasp on how many watts to compare to a DE. He has been doing this for decades and is dialed in. My last run (very small 750w) hit 1.1 gpw in organic soil at 20+watts per square foot. This test will be 50 watts per square foot.
@verticalgrow These were some HS that I payed way to much for to have custom milled to my specs. They are Starlites 600 watt HS that I had 2 6* angles milled into the mounting plate with the Citizen pattern. My thermal testing show that I get 95*c running each COB @ 250 watts. I am going to try some LED specific thermal compound as soon as I get it. They were close to $200 with a min. of 16. Then I got them, they are heavy.

nevergoodenuf said:

This isn't my room. It belongs to a friend that is willing to help me get a better grasp on how many watts to compare to a DE. He has been doing this for decades and is dialed in. My last run (very small 750w) hit 1.1 gpw in organic soil at 20+watts per square foot. This test will be 50 watts per square foot.
@verticalgrow These were some HS that I payed way to much for to have custom milled to my specs. They are Starlites 600 watt HS that I had 2 6* angles milled into the mounting plate with the Citizen pattern. My thermal testing show that I get 95*c running each COB @ 250 watts. I am going to try some LED specific thermal compound as soon as I get it. They were close to $200 with a min. of 16. Then I got them, they are heavy.

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Thx bro, do the heatsinks weigh over 3kg?

The 320's are 3.2 kg
The 600's are 6.4 kg

"but do have a lux meter that I will use to set the fixture heights @ around week 2"

What lux # do you feel is optimal for flower? I am at day 34 and i set my lights at approx 70,000 lux at the tops, using 2 different phones apps might not be balls on but should be close.

I have been moving closer to 200,000 Lux across the whole canopy. Running at 160w I hit 200,000 lux @ a bit over 12"

nevergoodenuf said:

I have been moving closer to 200,000 Lux across the whole canopy. Running at 160w I hit 200,000 lux @ a bit over 12"View attachment 3898262

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Wow, I wasn't expecting that answer. From everything I have read plants can't exorb much over 108,000 lux. What am i missing ?

@Pulpit_ Yeah, that's what I said when Starlite tested my lux meter. I have also compared to the rest of my friends room and everywhere (under SE and DE) he is hitting about 200,000 lux without CO2. I run CO2 in my room, so 950 still seems low to me.

Haven't made it up north yet, but I am going up tomorrow. I might change things up one more time. I just finish 950w light and may replace 2 of the fixtures with this. So it would still be the same power, just 2 fixtures. It hits 200,000 lux @ 26".

Loving those reflectors! Also, nice to see some well used work boots! Real man status!!!!

Your buddies ceiling needs anti mildew mold latex paint on it. Might even brighten it up more with flat white.

Looks good though!

Niblixdark said:

Your buddies ceiling needs anti mildew mold latex paint on it. Might even brighten it up more with flat white.

Looks good though

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Yeah, this year has been brutal on his rooms. Had a couple leaks in the roof that hasn't helped.

MediheaLed said:

Loving those reflectors! Also, nice to see some well used work boots! Real man status!!!!

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Those are my clean boots. This reflective aluminum is easy to work with, it's called Anomet (95% reflective). I get it by the 4'x8' sheet.

I went to my friends store to take some temps in their 5'x5' Gorilla tent. The only air moving is from a wall mount fan in the tent, no intake or exhaust and left it closed up for a couple hours. And the lux meter is 40" away. Heading north shortly.

Wow, what a couple weeks will do. I now wish I didn't use the fixture with the 4000k 70cri. It looks much smaller and thinner than everything else. I put the new 950w 3000k 90cri fixture over the shorter plants and have the other 2 fixtures now running @ 500w each, so still under 2000 total watts. Tomorrow the plants will get cleaned up to the lower net. Almost identical on the back end, away from the 4000k.

Looks good, gonna follow this one... Ive got some 4000k 70cri cxb3590s that Im not happy with, replacing them with citizen 1212s 3000k 90cri... Not the first $$$ Ive wasted playing with LED unfortunately. Might turn them into reef lights for a buddy of mine thats into saltwater aquariums...

They make great work lights. Why such a small COB? J/K
Yes, 3000k 90cri are kicking ass. They are the back wall and now both ends with 3500k 80 cri in the middle. I am hoping the 950w will help this end catch up. 970 ppf @ 25" and I don't have 25"

nevergoodenuf said:

They make great work lights. Why such a small COB? J/K
Yes, 3000k 90cri are kicking ass. They are the back wall and now both ends with 3500k 80 cri in the middle. I am hoping the 950w will help this end catch up. 970 ppf @ 25" and I don't have 25"

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Its a constant current driver and the way I have it set up I cant go over 36v/cob without rebuilding the whole thing... Those little 1212s can handle some pretty good power tho, Ill be pushing them to 1750ma. Also got them for $10/each shipped, not too shabby.

what is distance of your cobs to canopy? im trying to dial in my DLI. Acceptable ranges im finding seem to range from 25-30 DLI. I saw one place mention up to 40 DLI? 720ppfd is about 30 DLI. 940ppfd is 40 DLI.

To calculate DLI, multiply ppfd by .0432

I removed a light from my tent yesterday to dial it down to about 740

Average DLI in the US, outdoor, is 30