Light Advice, Please

The Bard said:
Thanks again. I am going to keep doing some research. The quick search I did seemed to suggest that 315W CMH is good for 4x4 in veg, but only 3x3 in flower. But perhaps different bulb types and reflectors influence that. More of a concern for me is the clearance/heat question. Definitely not ruling out a CMH at this point - curious to read more about them. Thanks again for floating the idea!
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Heat can still be an issue with cmh.
Im running a 630 watt sunsytem dual bulb open hood in my 4x4 x 6.5 tent. Will definatly have to change lights or invest in a smalll a/c unit if i want to continue to flower through the summer months as my 6" extraction fan is already running the whole 12 hour on cycle.

My advice if you wana go cmh.. get an air cooled hood..

I'd love to hear what some people might have to say about the heat output from a similar powered LED option.
Would probably want to go with at least 900 watt LED up to 1200 watt LED for flowering in a 4x4 based on what iv been reading
 
Electric sky es 300. Very low profile. No fans or moving parts. Sleek design. Very fast shipping in Canada. They also offer an es180. The growth on my plants has been amazing so far.

I have 2 es300 in a 4x4 room. I had to add a small heater to keep my room in the mid 70f range. They run cool. Nice light.
 
captaincronik said:
Heat can still be an issue with cmh.
Im running a 630 watt sunsytem dual bulb open hood in my 4x4 x 6.5 tent. Will definatly have to change lights or invest in a smalll a/c unit if i want to continue to flower through the summer months as my 6" extraction fan is already running the whole 12 hour on cycle.

My advice if you wana go cmh.. get an air cooled hood..

I'd love to hear what some people might have to say about the heat output from a similar powered LED option.
Would probably want to go with at least 900 watt LED up to 1200 watt LED for flowering in a 4x4 based on what iv been reading
Click to expand...

Yes, I have pretty much ruled out a CMH type at this time. Mainly for height limitations, but also for heat. I could get around the heat issue, but the height I am stuck with!

I thought that the rule of thumb was 30-40 true watts/sqft. For a 4x4 (16 sqft), I had been thinking that 480-640W (real watts, not fake claimed LED watts) would be a good target. I am definitely no expert, but it seems like 1200W for a 4x4, or 75W/sqft would be more than needed? If I am wrong with this rule of thumb (30-40W/ft) I'd appreciate some more information. Thanks!
 
The Bard said:
Yes, I have pretty much ruled out a CMH type at this time. Mainly for height limitations, but also for heat. I could get around the heat issue, but the height I am stuck with!

I thought that the rule of thumb was 30-40 true watts/sqft. For a 4x4 (16 sqft), I had been thinking that 480-640W (real watts, not fake claimed LED watts) would be a good target. I am definitely no expert, but it seems like 1200W for a 4x4, or 75W/sqft would be more than needed? If I am wrong with this rule of thumb (30-40W/ft) I'd appreciate some more information. Thanks!
Click to expand...
There are lots of lights that fit what you're looking for. My cob led is kicking ass. 450 real watts
 
The Bard said:
Yes, I have pretty much ruled out a CMH type at this time. Mainly for height limitations, but also for heat. I could get around the heat issue, but the height I am stuck with!

I thought that the rule of thumb was 30-40 true watts/sqft. For a 4x4 (16 sqft), I had been thinking that 480-640W (real watts, not fake claimed LED watts) would be a good target. I am definitely no expert, but it seems like 1200W for a 4x4, or 75W/sqft would be more than needed? If I am wrong with this rule of thumb (30-40W/ft) I'd appreciate some more information. Thanks!
Click to expand...
Yea im also no expert.. when i say 900 - 1200 watts. Thats what theyre " advertised" at.. actual pull is different..

Always lots of learning to do as this difference in a rating and what they actually pull from the plug always confuses me
 
captaincronik said:
Yea im also no expert.. when i say 900 - 1200 watts. Thats what theyre " advertised" at.. actual pull is different..

Always lots of learning to do as this difference in a rating and what they actually pull from the plug always confuses me
Click to expand...

Yup! I think it is wise to compare based on the "true" numbers, versus the claimed watts, which seem just to be made up...
 
The Bard said:
Yup! I think it is wise to compare based on the "true" numbers, versus the claimed watts, which seem just to be made up...
Click to expand...
Yeah but they've been getting better at providing the info. I'd say steer clear of companies that don't advertise true watts. There's always someone who can confirm or deny their claim
 
The Bard said:
Yes, I have pretty much ruled out a CMH type at this time. Mainly for height limitations, but also for heat. I could get around the heat issue, but the height I am stuck with!

I thought that the rule of thumb was 30-40 true watts/sqft. For a 4x4 (16 sqft), I had been thinking that 480-640W (real watts, not fake claimed LED watts) would be a good target. I am definitely no expert, but it seems like 1200W for a 4x4, or 75W/sqft would be more than needed? If I am wrong with this rule of thumb (30-40W/ft) I'd appreciate some more information. Thanks!
Click to expand...

I go by watts per PAR light produced. As the efficiency of the light is the most important factor. The 30-40 watt/square foot is only still good for old type of lights like HPS.

With COB's like mine you would only need at most 660 watts of power during flower. And during veg you could have them dimmed down to next to nothing . Four one hundred watt cob's in the corners with 2 in the middle.
 
Grassmaster said:
I go by watts per PAR light produced. As the efficiency of the light is the most important factor. The 30-40 watt/square foot is only still good for old type of lights like HPS.

With COB's like mine you would only need at most 660 watts of power during flower. And during veg you could have them dimmed down to next to nothing . Four one hundred watt cob's in the corners with 2 in the middle.
Click to expand...

Could you post a link to a product similar to the ones your speaking of.

I want to look into the led thing..
The tech is advancing quickly amd theres alot to consider when looking at leds
 
600 true watts in a 4x4 and I'm getting multiple colas over a foot long. I may add supplemental red flowering lights later on but I am pretty happy using 2 300watt led in a small room.

HLG seems to be one of the highest quality lights out there. Happy with 2 electric sky es300 but am going to buy an hlg for my second room to try out. I dont think you can go wrong with any of the "higher end" lights out there. They will pay you back quickly. These are all auto flower blueberry. One is over 4ft tall.
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captaincronik said:
Heat can still be an issue with cmh.
Im running a 630 watt sunsytem dual bulb open hood in my 4x4 x 6.5 tent. Will definatly have to change lights or invest in a smalll a/c unit if i want to continue to flower through the summer months as my 6" extraction fan is already running the whole 12 hour on cycle.

My advice if you wana go cmh.. get an air cooled hood..

I'd love to hear what some people might have to say about the heat output from a similar powered LED option.
Would probably want to go with at least 900 watt LED up to 1200 watt LED for flowering in a 4x4 based on what iv been reading
Click to expand...

I have a SunSystem 315 CMH that I now only use in the winter. They give off infa red and are perfect to keep your plants warm in the winter. But as soon as normal temperatures arrive I switch to my Migro 4 COB set up.

The COB drivers are outside the 3'by 3' tent. COB's give off much less infa red, lighting is much more even with higher PAR. They are dimmable and they have a much higher efficiency of 2.0. Much easier to control the heat and the plants can go to higher temperatures without damage.
 
Grassmaster said:
I go by watts per PAR light produced. As the efficiency of the light is the most important factor. The 30-40 watt/square foot is only still good for old type of lights like HPS.

With COB's like mine you would only need at most 660 watts of power during flower. And during veg you could have them dimmed down to next to nothing . Four one hundred watt cob's in the corners with 2 in the middle.
Click to expand...

That is good to know! I've actually started using PPFD as a measure to compare different lights that I have been considering. I *think* it is one of the better metrics for evaluating what the plants actually use? Not all manufacturers have a PPFD quoted in their materials though.
 
The Bard said:
Yup! I think it is wise to compare based on the "true" numbers, versus the claimed watts, which seem just to be made up...
Click to expand...
The advertised wattage is the number of diodes x the max run power of them. Ie 100x6w diodes would be advertised as a 600w light. Just that if they ran at full power they wouldnt last long so they use drivers that only push them at usually around 40-45%ish. So the 600w light becomes a 240w light.
 
raymont said:
2 "Chinese' 240 watt knock offs on the walls, one with infra red. One without. One knockoff 600 watt "SPYDRx on top. 4x4 and it requires air conditioner cooling.. The lights seem fine quality wise and plants are growing mad..So bright you need sun glasses20190314_143021(1).jpg
20190314_143021(1).jpg
Click to expand...
Hmm... not sure why ive never thought of hanging them at the sides too. Ive got 4 x 250w panels sitting spare. MIght have to give that a bash this time, i tried using them uptop but once i got passed about 80w per square foot it went downhill pretty quick. Stressed my babies right out.
 
Your all still running 600w in 4x4 with LED, Im doing same area with 315w, will run cooler.
Also, you can get remote ballast set ups to just have a light in tent, ballast external.
I ran one 315w cmh thru summer easy.
 
Lowrider72 said:
Your all still running 600w in 4x4 with LED, Im doing same area with 315w, will run cooler.
Also, you can get remote ballast set ups to just have a light in tent, ballast external.
I ran one 315w cmh thru summer easy.
Click to expand...
500w for me and my 10 year old blurples. Get upto 600g per plant with them. Tried and tried to get the same yield with 600w hps and 600w cmh. Can't even get close no matter what I do. Got 1 more try with the HID, if I can't match it im gonna upgrade all 7 of my 600s (250w) with cobs. Well, my trusted sparky is gonna do it in exchange for some smokeables anyway. I'd burn the house down lol
 

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