Written by,
-Nathan Kurt Hardenburg
aka The Rainbow Rogue Cultivation Phenosmith
PCOB (Phosphor Chip On Board) is a COB or MCOB (Multi-Chip on board) LED Light-Engine that has a specific ‘Phosphor’ layer added over it, in order to tune the spectral output aka “color-temperature” of the light more suited for plant growth.

somewhere between COB and MCOB

somewhere between COB and MCOB

If you understand what PAR is, then really, you don’t need any testimonials or “grow videos” to show how well these will work. They are tuned for PAR, also known as PPFD, measured in micro-moles (umols) aka Einstein’s.
I had already used some of the smaller “NASA red & blue” LED grow lights with good success for vegging, but for flower in MMJ I needed more power. When I looked at the 7 band MCOB verse the Epistar PCOB, the spectral output is fuller, a smooth curve instead of the spikes which correlate to the wavelengths of maximum return in terms of what the plant needs (Photo A&B, UV-IR, etc.). There is a small price difference, and the MCOB’s are more expensive than the PCOB’s, I know the Chinese are not incapable, the seller’s websites simply state the MCOB is better for MMJ. I had thought perhaps that the Phosphor layer would act as an extra encapsulation, possibly protecting the bond-wires more than the standard MCOB.

I have noticed using the 50Watt PCOB’s, that growth is explosive verse the 400 watt HPS/MH and 250w Magnetic Induction grow lights I have previously used. The flowers are tighter and heavier, causing me to have to stake my plants at the end of flower, and my fruit-bonsai’s love this spectral tuning as well.

I have noted that the Epistar chips are more rugged than the Bridgelux, in that they survived my abusive inadequate heat-sinking. I also noted that the Bridgelux have more power towards the blue spectrum verse the Red when compared side by side to the Epistar.

I recommend that people buy the sets of Lens + Heatsink off EBAY and Aliexpress, it’s cheaper and better in the long run, make sure to use a THIN coat of heat-sink grease, just use the Arctic Sliver (it’s the best). If you cake-on the heat-sink grease it tends to dry-out and stop conducting properly, just remember that it’s filling the microscopic cracks and crevices between the two mating surfaces. The Lens is better, if for no other reason, you can back the light off of the canopy more, making it easier to water, prune and check for any problems with your plants.

Contributed by,
-Nathan Kurt Hardenburg
aka The Rainbow Rogue Cultivation Phenosmith


About the author

15 years horticulture experience to draw from
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