For my thesis, I am cultivating a species of Algae known as Chlorella Vulgaris. C. Vulgaris is known and studied for scrubbing CO2 as well as producing oil that can be used as biofuel. Its also consumed by humans as a ‘superfood’. I ordered C. Vulgaris from Carolina Labs. I went with the simplest instructable I could find to create a DIY bioreactor, found here. After creating the reactor, I followed pretty generic sanitation procedures: sterilize the bioreactor with alcohol then flush with hot water; gloves, sterile instruments, etc.
To grow, the algae needs (per Carolina) 200-400 foot candles of light for 7-10 days in circadian cycles (12 on/12 off). Formulas for light conversions:
lumens = foot candles x 10.76
Watts = lumens x 0.001496
I ended up with only needing about 6 and a half watts of either incandescent or fluorescent light (contains UV).
The algae also needs a fresh supply of CO2 hence the aquarium pump, as well as some nutrients. For the nutrients I just bought some fresh water plant food from the fish store and am giving 2-3 drops weekly.
To automate the lighting system, I set up an Arduino running the Blink without Delay code from the Arduino library. By using a power switch tail (which does the hard stuff of going from DC to AC current for the clip light) I can simply send a pulse of voltage on for 12 hours and then off for 12 hours. To see what problems may arise, I added on a Sparkfun micro sd shield and an adafruit chronodot RTC. The RTC is a really accurate clock that has its on Lithium battery, so that time is kept accurately and uninterrupted. I am writing the on/off values with a time stamp the entire time to a csv. Its really unsophisticated but it does the job in a pinch. You can see the code on my github here.
The wiring is pretty straightforward. The RTC runs on I2C communication and the RTClib Library specifies using analog pin 4 to SDA. analog pin 5 to SCL to accomplish this.
I’m currently on Day 4 and the are growing well. A decent setup. Now, for my biofluorescent marine algae…















