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cool white LED


New Member
I special ordered a few cool white LED 3w x 100 from topLED. I plan to run a few experiments and wondered if anyone else has had any experience with full white LED's?

I bought these are a few reasons...

No matter how close to t5 you are, you can never get over ~ 550umol. I would like to do some tests with much higher umol and these fixtures go up to 2000+ depending how small an area and in almost all plant conditions, plants cant use much more than 1500 so im max topend.

I really like my t5's but looking for a more efficient and cheaper replacement. Bulbs on t5 have mercury and only last 8-10 months before the math says replace them. 5 years+ would be a great improvement on cost.

The cool white light is much more pleasant to work around than pinkish glow of LED's.

It seems all the luminosity records are for white leds and thinking white has the highest output/watt/$.

Im interested in the large LED COB and other high powered chips and thought i would start with some these white LEDs to have some reference.


New Member
Are you using them for veg only? If so they will work rather well. The new Bridgelux Vero and Cree COB's are pulling some amazing numbers. If you are wanting to flower you will want to go with warm white and a few reds to assist at a minimum.
yes veg. I use my t5's as veg also for seedlings, herbs and other leafy greens. I considered buying some warm whites to compare but these were already expensive with shipping and engineering so i figured test cool first. I also like the idea of adding reds to whites and have already discussed that option with them in the future.

Definitely cooler running than t5's. And if the spectrum and durability works out, they would be considerably cheaper in the long run over t5's as those bulbs dont last. The cool white LED's also are more 'whiter and brighter' than the t5's, which im not sure if a good or bad thing.

In my experience, the t5's cool white seem to be better for veg than the full spectrum and 'veg' spectrum LED's from topLED. Both LED's will veg just fine but the plants seem happier and healthier under t5's cool white, no matter the intensity. I use no warm reds in veg room.

I also like the idea of using COB white for DLI maintenance in the greenhouse. COB integrated into the superstructure of the greenhouse seems an ultimate efficiency.


New Member
Don't forget that root growth and some enzymes require red light. Likewise, there are some seeds that require light to sprout and there are a number of studies that show deep and far red is much more efficient at doing so (this is not the case in cannabis). I don't have the datasheet for the cool whites you are using, but most have enough low red (610-630nm) to perform most plant functions.
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