[justbuchanan]

I'm looking into building an LED lighting setup for my vivarium and am curious about the new "Photophyll Select" LEDs from Cree. Their spectral output is optimized for growing plants and are intended to be paired with red LEDs to cover the whole photosynthetic spectrum. More details here: https://assets.cree-led.com/a/fs/Cree-LED-Horticulture-Feature-Sheet.pdf.

Does anyone have experience with these LEDs? I haven't been able to find any posts online of people using them for terrariums/vivariums. I'm interested in also adding some warm and cool white LEDs on separate channels so I can do sunrise/sunset effects. My biggest open question right now is how to figure out the right ratios of these different LEDs to use.

Thanks!

 

[NorCal Frogger]

I have extensive experience with LED plant lighting, I owned a business that manufactured LED lights for horticulture. I also have a degree in biology, my wide is a botanist, and I have designed several cannabis facilities.

Generally, plants care far more about having the correct quantity of light than they do finely tuned spectral qualities. There is plenty of peer reviewed research comparing the dry ash weights of plants grown under different spectra to support this. However the quest for the very best possible plant lighting is fun, and therefore worthwhile.

The addition of far red lighting to horticultural LED lighting is of value do to the Emerson effect. It is a real, measurable effect, but economically if you were producing produce for instance, the increase in product that would result from fully leveraging the Emerson effect will not always make for a good ROI on the additional cost of far red diodes.

You may have heard the adage "fishing lures are designed to catch fisherman rather than fish". This is very much the case with LED plant lighting.

Because vivariums are for our viewing pleasure, lighting with a good color-rendering index (CRI) is arguably favorable to a spectral output that is designed only with the McCree curve and Emerson effect in mind.

I see that the CRI on those diodes is 70. Not great. Something like a Samsung 301B or 301H diode could provide excellent plant lighting and CRI of 90 (not all 301's have CRI 90). I have a vivarium with 301H diodes and when I posted pics here, people commented on the stunning colors in my broms. It's not that my broms are more vividly colored than others, but good CRI makes colors really pop.

To answer your question regarding spectral ratios; whatever looks best to the human eye would be my suggestion. If you were to use a light meter like the apogee epar sensor, while varying the ratios of spectra, you would not see an appreciable difference in PPFD.

Hope that helps.

 

[Simon85]

I'm not a big fan of led lights which have blue, red and green diodes etc. I bought some skylight leds in a panic when my main panel broke down. My plants seems happy but I prefer having white light from a high cri led light instead as you won't get any weird shadows with those.
I have built a led panel using these 98 cri Yujiled modules YUJILEDS® CRI 98 8.6W LED Linear Module - 10pcs — YUJILEDS High CRI Webstore (yujiintl.com) .
They do have led diodes which are not attached to modules as well.