Archive for Growing Algae

Algae Advice: Getting Spirulina to Grow.

Hello Algae Fans,

From time to time I will solve specific algae conundrums, such as this one. See if you can figure it out, then at the end I’ll tell you the solution!



I am interested in growing my own spirulina platensis at home. I have constructed a 3 foot tall 6 inch diameter acrylic grow tube for this purpose. I recently ordered a small culture of spirulina platensis from the University of Texas. I did everything I could to maintain this highly diluted culture. I started with a very small quantity of distilled water based media, utilizing pro algae culture formulas parts a and b. I ran a 125 watt compact florescent grow light through the culture for 12 hours a day. The result was a sticky yellow algae that did not resemble the typical characteristics of healthy blue green Spirulina. I did run a slight stream of bubbles from the bottom of the tube 24 hours a day to stir the mix and provide carbon dioxide and I can confirm that there was no other algae contaminating this growing tube. Can you provide any insights into where I may have gone wrong. I am interested in purchasing a more robust culture from you at but I don’t want a repeat of my last efforts. Any info you can provide me would be extremely helpful.

p.s. I did keep the culture at an almost constant temperature of 82 degrees F


Hello Chad,

Cheers for giving it a go! Sorry to hear it didn’t work; those UTex cultures are pretty pricey. Glad you found us! I’m curious where you got your information about how to grow Spirulina, though; see if the below advice helps.

The Pro Algae culture formula, like all other general algae-growing media, is not very good for growing Spirulina, especially because it lacks carbonate and bicarbonate. The types of Spirulina grown for food thrive in natural soda lakes, the water of which is very rich in natron, a substance rich in both sodium bicarbonate (baking soda) and sodium carbonate (soda ash). Spirulina medium always contains a lot of one of both of these ingredients; our starter mix provides 16 g of baking soda per liter of medium.

The soda pushes up the pH to 10+, which is the range that Spirulina likes best. You also made the situation worse by bubbling in carbon dioxide, which lowers pH. The addition of carbon dioxide to algae medium must be monitored closely using a pH meter.

And two more things that would have also impacted the growth of your little guys: the nutrient ratios in Pro Algae are not optimized for Spirulina, and 82 degrees is generally sub-optimal for Spirulina – they prefer higher temperatures, generally closer to body temperature (97F).

Hope this helps. If you do order a kit or bottle from us, you’ll get detailed instructions and recipes for our nutrient powders as well. We’ve gotten a lot of people going who have no experience at all, so I’m sure we can get you up and running!

From the heart of the chloroplast,

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