Spirulina FAQ

For the growing stage, all you’ll need is:

A large tank or aquarium
Water pump
Water heater
Air pump
PH/ temperature Meter

To prepare your spirulina’s nutrition, you need:
– Lots of good, clean water
– Bicarbonate soda
– Sea Salt
– Iron Drops
– Some ash from natural wood, mixed with water
– Some urine, preferably from someone in good health or from a child

It depends on the culture volume and the size of your tank. When the water level in your tank has reached full capacity, you can stop adding culture medium and wait for the water to thicken with green, which should take about a week.

Spirulina harvest can be done by either pumping your tank water through a thick cloth or sieve and letting it drip until a cheese like paste is left in your filter. Alternatively, if your culture is really thick and clumpy, it can easily be scooped with a spoon. Its important to only eat clumps that are dark green though, and always replace what you’ve extracted with adequate proportions of culture medium.
To learn more about how to harvest your spirulina safely, please refer to our book “Be The Medicine- A guide to Growing Organic Spirulina At Home”.

If you have too many bubbles in your tank its probably due to one of two things:
1. Your air pump has been operating for too long. Air pumps should only work for about 2 hours a day, and in periods of 1/2 hour each time. You can do this using an electric timer so you don’t forget to turn it off.
2. Another thing that could cause too many bubbles to appear is wrong nutrition proportions. To correct this, ad a little bit of ash water, stir, and see what happens. If several hours later you still see the same bubbles, you may need to add some culture medium.

If the clumps floating in your tank are dark green and healthy looking, you win! This means you haven’t been harvesting often enough. Clumps can be harvested without going through the long process of filtering spirulina of the water, but try not to repeat that too often because overtime, it will turn your filaments from coiled to straight, which is not desirable. Just harvest more often and it’ll sort itself out. Bare in mind if the clumps are grey, brown, or white, they are not suitable for eating. Scoop them out and use them as a plant fertilizer.

Since organic culture medium contains urine, it doesn’t keep for more than a few days. If the culture smells bad- DO NOT US IT! Make a new batch and use it within 24 hours. If you don’t want to be making new culture medium each day of the growing stage, you can mix all the other ingredients, and add the urine just before you use it.

Yellow spirulina indicates unsuitable growing conditions. It could be that the temperature is too high or too low, not enough movement in the water, or bad culture medium proportions. If your spirulina has turned yellow, we recommend you to separate it into several containers and try different things to see what works. Either way, yellow Spirulina is like a child who’s ill, and should be treated with lots of loving care.

Spirulina thrives between 30-37 degrees Celsius. That’s 86-98.6 in Fahrenheit.
She’ll DIE at 42 degrees, but anywhere in between she’ll probably survive.
If the temperature is lower than 25 degrees, she would still be growing, but not as quickly,
And bellow 15 degrees she would not grow at all.

1 liter is enough to start your culture with, given that you feed it properly and provide it with the right conditions.
What is the color of your culture? is it still dark green or has it gone yellow? if the color is still green then you’d be fine with what you have.
Yellow culture can also be revitalized in some cases but that would require a more intensive care.

Question:
I am from Canada and grow spirulina and prefer to make/mix my own nutrient solution. I bought a live sample and instruction manual from a Canadian supplier in Ontario. I have no trouble growing spirulina in a new batch of solution however struggle with maintaining the culture after harvest. Cannot seem to make a proper nutrient solution mix to maintain an ongoing culture.
One of the hardest nutrients to find to grow spirulina is potassium nitrate. Its highly regulated and requires special permits to buy. I typically buy it on ebay in small quantities. I’ve read that UREA or even urine may be substituted instead of potassium nitrate as part of the nutrient replenishment solution after harvest. Apparently if using UREA it must be done so with caution.
So my two questions are as follows:
1 Does the book explain how to use urea as part of the nutrient replenishment mix after harvest which may reduce or eliminate the need for potassium nitrate?
2 Does your DIY book explain how to go about finding some of these necessary yet hard to find nutrients/fertilizers or recommend alternative substitutes using household chemicals. For example one fellow on Youtube recommends placing a few nail-spikes in vinegar and use the resulting solution for iron.
Thank you,
Terry
Answer:
Hi Terry,
Thanks for connecting with us. indeed, maintaining the culture after harvest tends to be the difficult part of growing spirulina. Did you make sure the water is warm enough? I know that in Canada this could be a problem. The ideal temperature is around 32 degrees Celsius.
In my book, I explain how to grow spirulina without any chemical nutrients, because personally i find it to be safer and better. This is of course a matter of controversy and taboo because as you mentioned, we replace the potassium nitrate or urea with human urine. While this may seem unhygienic to some, it is in fact far cleaner than any chemical fertilizer you can find on ebay, and all you have to do to keep is clean is maintain a healthy diet.
All other ingredients are either food grade or from natural resources, and can easily be found anywhere in the world.
As for making the iron solution, yes, some people soak rusty nails in vinegar and it works, but I prefer to use Iron drops which i buy in the pharmacy, because its easier to measure and its food grade, just make sure its 100% iron and doesn’t contain any other additives.
Hope this helps :)

Spirulina thrives on a PH level which is above 10.5, so as long as you maintain that level, no other microbes will be able to survive those conditions.
If you suspect that your culture has been contaminated, you can raise the ph to above 11, which will slow down Spirulina’s growth, but will destroy any unwanted organisms while maintaining the spirulina alive.
once you have ensured it is no longer contaminated you can take the ph back down to 10-10.5.