- Thread starter
- #461
While we're on the subject of lighting, I can share some rules of thumb.
You want 1200 umols at the top of the canopy and 500 at the bottom - that's "perfect".
In a 4x4, with Samsung diodes, you need 120,000 lumens to get 1200 umols. That will provide a 2 foot effective canopy. Other light sources will require higher lumens because of the PAR differences.
A 1000DE hps delivers 140 lumens/watt. Single ended hps are 130 Lu/W. CMH has a great spectrum but it only gets 115 Lu/W. COBs and Samsungs run at 150-200 Lu/W depending on how hard you drive them. My setup is nominally over 190, and I lose 7-8% in drivers, etc, so I get 170+ at the wall.
Let's see if I can format this in a way we can read it ...
..................Lux/ppfd....Lu/W.....factor
Grolux floro .......34 .......30 .......0.87
sunlight ..............54
blurple ...............55 ......110 ......2.01
CMH Agro ..........59 ......100 ......1.70
CMH ...................65 ......115 ......1.77
LM561c ..............66 ......180 ......2.72
Cree3590 ...........66 ......170 ......2.55
MH .....................71 ......110 ......1.55
Fluoro(cool white) 74 ....65 ......0.88
1000DE .............77 .......140 ......1.82
600HPS .............82 .......130 ......1.59
You want 1200 umols at the top of the canopy and 500 at the bottom - that's "perfect".
In a 4x4, with Samsung diodes, you need 120,000 lumens to get 1200 umols. That will provide a 2 foot effective canopy. Other light sources will require higher lumens because of the PAR differences.
A 1000DE hps delivers 140 lumens/watt. Single ended hps are 130 Lu/W. CMH has a great spectrum but it only gets 115 Lu/W. COBs and Samsungs run at 150-200 Lu/W depending on how hard you drive them. My setup is nominally over 190, and I lose 7-8% in drivers, etc, so I get 170+ at the wall.
Let's see if I can format this in a way we can read it ...
..................Lux/ppfd....Lu/W.....factor
Grolux floro .......34 .......30 .......0.87
sunlight ..............54
blurple ...............55 ......110 ......2.01
CMH Agro ..........59 ......100 ......1.70
CMH ...................65 ......115 ......1.77
LM561c ..............66 ......180 ......2.72
Cree3590 ...........66 ......170 ......2.55
MH .....................71 ......110 ......1.55
Fluoro(cool white) 74 ....65 ......0.88
1000DE .............77 .......140 ......1.82
600HPS .............82 .......130 ......1.59
Cheers 
I just love the way he explains it. Like Amy, I’m beginning to retain more and more with every reading. 
