COB suggestions for a small veg/propagation tent

velvet_underground said:

What are you using to measure PPFD?

Click to expand...

It's (normally) based on manufacturer data. I haven't converted the SPDs for the Citizen cobs I'm using, but LER of around 320-330 would put them at about 60% efficient at full power and around 65% efficient at 60 percent power. That's used to find par watts, and then multiplied by the QER... which I also don't know, but probably in the 4.5-4.8 range. That gets us the PPF which can be factored by space to determine the PPFD.

The actual PPFD range low and high (2700K 90CRI, 3000K 70CRI) at full power will be somewhere around 1300-1500, maybe a little more. It wouldn't be that difficult to get some exact numbers but I have no plan to sell Citizen cobs so didn't see the need to digitize the 5 spectrums. Loose math I know but the PPFD isn't important in the test, only that all the subjects are growing under the same output wattage.

@velvet_underground What cobs did you end up going for?

I just put two 6500k Citi 1212's @ 1400mA in the veg space of my cab (45cm W x 55cm D x 80-ish cm H). I was afraid I might have went overboard with the 6500K, but I hope they'll work fine. Maybe I should buy a couple of lower K cobs as well, it might be nice to be able to change my spectrum depending on if I'm running a stretchy or low and bushy strain. For 13$ each it is certainly worth a try.

I haven't looked too much into the whole reflector thing, but it seems like I should. In the meantime, after reading this thread, they are coming off