LEDs for plant/moss growth?

[victorhooi]

I’m looking at getting a PioReactor to do some cool experiments with plants/moss =).

However, that means I’d need to add a LED for photosynthesis.

The Pioreactor documention mentions you can use a 5mm LED - I think this is just one of those basic low-powered through-hole LEDs used as indicators, right?

Using additional LEDs | Pioreactor Docs

I was wondering if it’s possible to use something a bit more suited for photosynthetic experiments - like the Samsung horticultural SMD LEDs, which are pretty efficient (230 lumens/watt):

LM301H | SAMSUNG LED | Samsung LED Global Website

https://www.digikey.com.au/en/products/detail/samsung-semiconductor-inc/SPMWHD32AMH5XAT5SL/12083585?srsltid=AfmBOopdlSsHPKBCT5r8Gh1EmNZgg5te3tRVfkUk_4iAZrM8a30kHPc9

Does anybody know of an easy way to get say, a single SMD LED onto the PioReactor somehow?

Also - what voltage/current is available for that LED circuit?

The Samsung LM301H runs at about 0.2W (Vf = 2.7, I = 65 mA) - would the PioReactor be able to handle that power and heat dissipation easily?

[gendor]

While I love those LM301H LEDs for my indoor hydroponics setup, I think they may be a bit overkill for the Pioreactor.

The through-hole LEDs mentioned in the Pioreactor docs were set at around 5% intensity:

Using the Pioreactor for algae growth

Hi @gendor, I’m pretty sure we used these: Super Bright White 5mm LED (25 pack) : ID 754 : Adafruit Industries, Unique & fun DIY electronics and kits However, we had a similar problem where were overexposing our (dilute) cultures to light, and only saw growth when we brought the LED intensity down to ~5% or something (and brought it up from there). I think we also used a higher RPM than we initially expected, like 500.

I’ve tried using an LED similar to the LM301H that’s used in the Adafruit AS7341 breakout board (which can be attached to the Pioreactor window) after someone else reported using it:

Normally on spectrometer led

I would like to use the LED in the spectrophotometer to grow algae. However, the LED is currently only lit during measurements. Is there a way to keep the LED on continuously and have it turn off briefly when taking OD measurements? Any suggestions or guidance would be greatly appreciated! Thanks, David

and it bleached the spirulina I was trying to grow.

[davidhcsic]

Thank you. I ended up reaching the same conclusion. I suspect the superbright LEDs are also emitting too much light, which might be causing photoinhibition in most microalgae. Do you happen to know of any alternatives? Maybe something with lower intensity and a wider beam angle?

[gendor]

I got some superbright LEDs to try and replicate the experiment in the Pioreactor docs, and it was successful using spirulina platensis:

You can see how the growth rate stalls during the night cycle, and increases during the day cycle. This was at about 8%, so I think there is enough range to play with before you start getting into photoinhibition issues. Make sure you use the X1/X2/X3 pockets, as the other pockets have a much narrower beam.