Have any of you DIY COB Growers finished a crop under 1000W DE HPS? - POLL

Have any of you DIY COB Growers have actually finished a crop under 1000W DE HPS?

  • Yes

    Votes: 32 29.1%

  • No

    Votes: 78 70.9%
  • Total voters
    110
wietefras

wietefras

Well-Known Member
frica said:
I prefer to keep it pure umol vs umol and not speculate about spectrums.
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Don't forget the wall losses. With a HPS hanging 3' above the canopy, you lose a lot of light on the walls (or floor if there are aisles). So after initially already losing a minimum of 17% on the HPS reflector you will lose something like that again because of the wide angle beam and height.

You're lucky to get even 1.3 to 1.4umol/J from that HPS actually on your plants.

COBs can be much closer and even without optics their beam is much narrower. So much less wall losses there. and with COBs there is usually no need for reflector losses at all. So already there you will gain a lot on HPS. Even if the umol/J is the same.

Leds are also multi point lights giving much more diffuse light than HPS. Which means better penetration.

I have fixtures with old CXB COBs running at only 2umol/J and 800W of that already equals in harvest what I got from my Gavita DE boosted to 1150W (around 1200g). At 2.8umol/J really 550W to 600W should be enough to match that DE fixture.
 
CannaBruh

CannaBruh

Well-Known Member
wietefras said:
Don't forget the wall losses. With a HPS hanging 3' above the canopy, you lose a lot of light on the walls (or floor if there are aisles). So after initially already losing a minimum of 17% on the HPS reflector you will lose something like that again because of the wide angle beam and height.

You're lucky to get even 1.3 to 1.4umol/J from that HPS actually on your plants.

COBs can be much closer and even without optics their beam is much narrower. So much less wall losses there. and with COBs there is usually no need for reflector losses at all. So already there you will gain a lot on HPS. Even if the umol/J is the same.

Leds are also multi point lights giving much more diffuse light than HPS. Which means better penetration.

I have fixtures with old CXB COBs running at only 2umol/J and 800W of that already equals in harvest what I got from my Gavita DE boosted to 1150W (around 1200g). At 2.8umol/J really 550W to 600W should be enough to match that DE fixture.
Click to expand...
good points
 
ttystikk

ttystikk

Well-Known Member
CannaBruh said:
Upfront cost is more with LED
Upkeep cost is far greater with conventional HID
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Currently, this is true. It won't be true for much longer.

That's no reason to wait to buy LED light fixtures because as soon as you do, they start saving you money. At the price and quality now available, you'll always save more buying them over traditional lighting.
 
applepoop1984

applepoop1984

Well-Known Member
CobKits said:
well remember that hps uses 1100+W and on a system efficiency is only pushing 1.7 umol/J gross with less than ideal coverage.

with a far better spectrum i think 550W at 2.8 umol/J might approach the results of 1100W 1.7 umol/J - spectrum could give a 10% or more edge to the QB fixture

a 600H instead of a 480H driver pushing it certainly would, but then we're talking 750W
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Could you recommend a setup for me? It's a 2 foot by 2 foot by 4 foot high grow tent
 
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