ppfd cxb

can somebody tell me what my ppfd will be for a 20"x36" space? i will be running four 3500k 72v cxb 3590s at 700mA and one cxa2530 4000k at 1400mA for a total of 250w. it seams like it should be enough light but i want to make sure that i have plenty of light for an optimal yield

boostedhonda said:

can somebody tell me what my ppfd will be for a 20"x36" space? i will be running four 3500k 72v cxb 3590s at 700mA and one cxa2530 4000k at 1400mA for a total of 250w. it seams like it should be enough light but i want to make sure that i have plenty of light for an optimal yield

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Ok grasshopper...how many square feet is your grow space? Then divide your about 250 dissipation watts by that number.

4.98ft2, so 1245 ppfd which should be more than ample light

boostedhonda said:

4.98ft2, so 1245 ppfd which should be more than ample light

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Yes. About 50 dissipation watts a sq ft and somewhere above 25 PAR watts a sq ft is a lot a photons. Do you have a par meter or lux meter?

no par or lux meter, i have another tent with 700w of apollo panels( really only pulls maybe 300 from the wall) usually get about a gram per watt, i can tell these cobs are way brighter

boostedhonda said:

no par or lux meter, i have another tent with 700w of apollo panels( really only pulls maybe 300 from the wall) usually get about a gram per watt, i can tell these cobs are way brighter

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I was going to ask what you had been growing under. I have a blurple cheap led panel that is gathering dust with my hid ballasts and reflectors. I am continually amazed at the performance of 15 PAR watts a sq ft and a measured average 700 ish ppfd at the canopy. I think if this is your first go at white cobs you are in for a pleasant surprise.

As an aside, even at my relatively low power levels I have be watchful I don't bleach the top leaves.

boostedhonda said:

4.98ft2, so 1245 ppfd which should be more than ample light

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Interestingly enough, your average PPFD will be around 1200 µmol/s/m^2, but the way you came to that result is completely wrong.
You have to calculate total photon flux (about 550 µmol/s for your light) and the divide it by your area (0.465 m^2).

yea def have a prob with the blurple burning leafs and buds if too close

i have no idea how to figure this stuff out, thats y i asked for help

boostedhonda said:

i have no idea how to figure this stuff out, thats y i asked for help

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Aleah can show you how to calculate down to the photon. I'm just saying 25 par watts a foot will likely turn your girls bleached blonde! And you can get great results with far less. Are your drivers dimmable?

cxb3590s are dimmable 2530 is not

I dont see any reason to have that 2530 in there unless you need a heater....

im just using it for veg right now, thought it would give me a lil spectrum mix, but now hearing peoples replies i dont think im gonna need it for flower

hi