A Decision Needs To Be Made..

[Jimster]

Well led technology develops every day. If its putting out too much heat its not good tho. I’m running these on a 1,25cm heatsink. It is less than half inches. They are running pretty cool.
Don’t see much point in providing uv and ir. Uvc is completely filtered out by atmosphere in natural conditions and detrimental to all kinds of life. Uvb and uva supposedly increases the trichome production but it also damages everything in your grow area so uvless tent is better imo.
Far red and ir are not inherently bad but it produces too much heat and its not efficient to produce in a tent as they don’t correspond to any photosynthetic activity. Part of going with leds is to leave these unnecessary nms out to produce an even more efficient light. Its my opinion.

My experiments to date have just been messing around with components, at this point. The cob chips themselves need a heatsink...any higher power cob/led gets kinda toasty after 50 watts. I agree about a lot of the light being produced not having any real activity for the plants, but as fast as the technology is developing, it's only a matter of time I'm afraid. I LOVE the MH and MPS lighting...something theraputic sitting in the warm bask of the fake sun..

 

[scubascrog]

honestly I'd just do straight 3000k all the way through. works good for me

oh i see you built it :)

 

[crimsonecho]

My experiments to date have just been messing around with components, at this point. The cob chips themselves need a heatsink...any higher power cob/led gets kinda toasty after 50 watts. I agree about a lot of the light being produced not having any real activity for the plants, but as fast as the technology is developing, it's only a matter of time I'm afraid. I LOVE the MH and MPS lighting...something theraputic sitting in the warm bask of the fake sun..

Thats why, its good to have lots of chips scattered along your grow area imo, so you can divide up the power and run them more efficiently by driving them softer. Less heat and better distribution.
When all these lights up, they pull about 500w and i’m getting a 50-75k lux reading over the canopy at 14-16 inches i think. Admitted, my lightmeter is a cheap one but the last grow the nugs that were getting 50-60k lux were these (reading taken with the same lightmeter).

 

[crimsonecho]

honestly I'd just do straight 3000k all the way through. works good for me
View attachment 843664

oh i see you built it :)

Seems like its workin’ :)

I had a bit of elongation problems with lower Kelvins so we’ll see how this goes.

 

[Jimster]

Seems like its workin’ :)

I had a bit of elongation problems with lower Kelvins so we’ll see how this goes.

The total heat should be the same if you run a few chips hot, or many chips not as hot...but your point is made...they last longer when run cooler. It's going to be difficult to try LEDs after 30 years of HID, but hey...What would Jerry do?

 

[crimsonecho]

The total heat should be the same if you run a few chips hot, or many chips not as hot...but your point is made...they last longer when run cooler. It's going to be difficult to try LEDs after 30 years of HID, but hey...What would Jerry do?

Actually no it wouldn’t because the actual efficiency of each chip is rising when you run them softer and each chip converts less energy to heat (by percentage of the input power). So total heat output of 4 running at 25w compared to 1 running at 100w is different from one another, if the chips are the same.
Leds are good. If you don’t have cold temps and miss the warmth of hps, you’ll love them.

 

[scubascrog]

I may need to HPS my room this winter. we will see how my little 200W space heater runs up my temp :( my dwc temps are super low too. aquarium heater ftw.

 

[crimsonecho]

I may need to HPS my room this winter. we will see how my little 200W space heater runs up my temp :( my dwc temps are super low too. aquarium heater ftw.

I’m kinda battling with low temps too. Well not too much but its 22C and i would prefer 25 or so. Well maybe when all of them lights up in flower we’ll hit 25.

 

[MIMedGrower]

Great info and results here!

I too suffer from a cold environment and am still shy to switch to led. Even was going to get a qb for the 3x3 veg tent but it only gets to the low 70’s with 250 watts of t-5 fluorescent now.

I could do it with a 150 watts of led but I bet the tent would stay in the 60’s.

 

[Jimster]

Actually no it wouldn’t because the actual efficiency of each chip is rising when you run them softer and each chip converts less energy to heat (by percentage of the input power). So total heat output of 4 running at 25w compared to 1 running at 100w is different from one another, if the chips are the same.
Leds are good. If you don’t have cold temps and miss the warmth of hps, you’ll love them.

I love a good physics question! What you say regarding the better use of running several smaller leds at half power, such as 4x 25 watt at 50%, that setup would only provide 50 watts of usable power. Heat generation is a side effect (inefficiency) of the LEDs. If the efficiency between input wattage is the same in both chips (25 and 100), then they should deliver the same results. Regular light bulbs provide a good example. 4 100 watt bulbs run at 25% current will have the same heat and light output as 1 100 watt bulb run 100%, or a 1000 watt bulb run at 10%-but only if the efficiencies are the same (which they pretty much are for the sake of an example.) So...with LEDS, 100 watts of LED power is 100 watts of led power. Running 1 cob at 100 r 4 100s at 25% should be the same light output. Any differences is due to the chip maker's specs, with shitty LEDs developing more heat.
Please correct me if I missed the question. I spent most of my career in electronics and love to talk shop and I can be a pain in the ass at times...just let me know!:cool:

 

[crimsonecho]

Great info and results here!

I too suffer from a cold environment and am still shy to switch to led. Even was going to get a qb for the 3x3 veg tent but it only gets to the low 70’s with 250 watts of t-5 fluorescent now.

I could do it with a 150 watts of led but I bet the tent would stay in the 60’s.

Well yeah if you switch to leds you’ll go a lower wattage so the overall heat output may suffer but a cob ran at higher miliamps still puts out good heat.

 

[crimsonecho]

I love a good physics question! What you say regarding the better use of running several smaller leds at half power, such as 4x 25 watt at 50%, that setup would only provide 50 watts of usable power. Heat generation is a side effect (inefficiency) of the LEDs. If the efficiency between input wattage is the same in both chips (25 and 100), then they should deliver the same results. Regular light bulbs provide a good example. 4 100 watt bulbs run at 25% current will have the same heat and light output as 1 100 watt bulb run 100%, or a 1000 watt bulb run at 10%-but only if the efficiencies are the same (which they pretty much are for the sake of an example.) So...with LEDS, 100 watts of LED power is 100 watts of led power. Running 1 cob at 100 r 4 100s at 25% should be the same light output. Any differences is due to the chip maker's specs, with shitty LEDs developing more heat.
Please correct me if I missed the question. I spent most of my career in electronics and love to talk shop and I can be a pain in the ass at times...just let me know!:cool:

Was there a question :cool:

Those datasheets specify that when running cobs softer, luminous efficacy goes higher and total heat loss decreases by percentage. These are crees.
That setup would lose less watts to heat than a 50w single cob. When you drive them softer more light is produced watt by watt.
4 100 driven at 25 and 1 100 driven at its max can create considerable differences in lumen output.

 

[MIMedGrower]

Was there a question :cool:

Those datasheets specify that when running cobs softer, luminous efficacy goes higher and total heat loss decreases by percentage. These are crees.
That setup would lose less watts to heat than a 50w single cob. When you drive them softer more light is produced watt by watt.
4 100 driven at 25 and 1 100 driven at its max can create considerable differences in lumen output.

Also better coverage and diffusion with more points of light.

 

[crimsonecho]

Also better coverage and diffusion with more points of light.

Man i love leds :)

 

[MIMedGrower]

Well yeah if you switch to leds you’ll go a lower wattage so the overall heat output may suffer but a cob ran at higher miliamps still puts out good heat.

True. I figure I need to at least match my hps wattage in the flower room if I switch to cobs. Still a little pricey. I just got 2 new Solis-Tek 600w digi ballasts for $217 shipped. 250 more for top of the line reflectors these days and I have all new lighting for less than one side of led’s replaced including a few years of replacement bulbs.

By then the price wars and little guys should be done and the prices should come into reality for a solid state panel of plastic lights and a computer driver brick.

 

[MIMedGrower]

@CrimsonEcho I love growing. The lights are simply tools to fit the job.

Growers should consider all aspects before choosing which tools to use. All of our rooms and situations are different.

The universities like Michigan are testing crop specific spectrums with discreet colored chips. In time we will have specific choices or programs to choose to light our specific plants.

Just like specific ratio nutes for each kind of crop.

 

[crimsonecho]

True. I figure I need to at least match my hps wattage in the flower room if I switch to cobs. Still a little pricey. I just got 2 new Solis-Tek 600w digi ballasts for $217 shipped. 250 more for top of the line reflectors these days and I have all new lighting for less than one side of led’s replaced including a few years of replacement bulbs.

By then the price wars and little guys should be done and the prices should come into reality for a solid state panel of plastic lights and a computer driver brick.

Well i’ve seen great results wih 30watts a square foot. I don’t know your square footage but it should cut your total wattage by 20-30% if you use the high efficiency stuff and run them softer and probably still get better results.
Yeah its an investment and the prices will come down surely but so will hid lighting as the leds take their slice. So there will alway be a reason to go with hid :)

 

[crimsonecho]

@CrimsonEcho I love growing. The lights are simply tools to fit the job.

Growers should consider all aspects before choosing which tools to use. All of our rooms and situations are different.

The universities like Michigan are testing crop specific spectrums with discreet colored chips. In time we will have specific choices or programs to choose to light our specific plants.

Just like specific ratio nutes for each kind of crop.

Yeah, i mean i was not against the blurples either. They’re scientificaly proven to work and provide good results at lower wattages.

The problem with blurples was, most of the actual fixtures and diodes were shit. They were low efficiency poorly made products.

Are they testing for cannabis? :D

 

[MIMedGrower]

Well i’ve seen great results wih 30watts a square foot. I don’t know your square footage but it should cut your wattsge by 20-30% if you use the high efficieny stuff and run them softer and probably still get better results.
Yeah its an investment and the prices will come down surely but so will hid lighting as the leds take their slice. So there will alway be a reason to go with hid :)

I would say they will eventually stop making bulbs but the music industry still makes vacuum tubes for amplifiers like they had in the old days.

Guitarists like the tube amps so the industry keeps making them. Digital modeling amps for all the benefits have not taken over in decades of improvements.

 

[MIMedGrower]

Yeah, i mean i was not against the blurples either. They’re scientificaly proven to work and provide good results at lower wattages.

The problem with blurples was, most of the actual fixtures and diodes were shit. They were low efficiency poorly made products.

Are they testing for cannabis? :D

Not the university of Michigan. Yet. We just voted rec so they can soon enough.

The u of m is like Cornell with all the agriculture studies.