Spirulina FAQ

The first thing you’ll need to get started is a spirulina culture. If natural Spirulina is available in your area, fetch a bottle and get going! Otherwise, Spirulina culture can easily be posted by mail, so look at our Live Spirulina shop to find your nearest supplier. Once you have your Spirulina culture, it’s best to get going right away or no longer than a week, because she grows quickly!

For the growing stage, all you’ll need is:
– A large tank, aquarium or pond
– Water pump, paddle wheel or aerator
– Heaters and lighting for colder/darker days
– Air pump
– PH/ temperature Meter
– Secchi disk to measure culture concentration

There are many different feeding formulas that you can use to cultivate spirulina. While the mineral composition may defer, these are the general components:
– Lots of good, clean water
– Bicarbonate soda
– Sea Salt variations that are high in magnesium like epsom salt
– Potassium source like ash from natural wood
– Nitrogen source like urea or urine

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. This process usually takes about 2 weeks, but it also defers greatly depending on the climate.

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. Remove and dispose of any brown clumps, wash twice and press the water out. Return the wash water back into the tank.
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 books Algae Bloom- A Handy Guidebook For Starting A Scalable Spirulina Farm, and 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.

Since the organic spirulina culture medium contains urine, it doesn’t keep for more than a few days. The chemical alternative, Urea, also tends to develop a smell of ammonia when it sits for too long.
If the feeding mix 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 together in advance, and add the nitrogen source just before you use it.

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.

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.
It’ll DIE at 42 degrees, but anywhere in between it’ll probably survive.
If the temperature is lower than 25 degrees, it would still be growing, but not as quickly,
And bellow 15 degrees it would not grow at all.

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 30-35 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.

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.

To answer your question, one must look into the environment where spirulina thrives naturally.

We are talking about volcanic soda lakes that are rich in minerals and salts, with hardly any organic material.

This creates the high pH which is crucial for spirulina growth, but it also prevents other organisms from growing within the same water.
When cultivating spirulina, we seek to resemble that natural environment as much as possible by adding the same nutrients or their synthetic analogs.

The culture is maintained at around pH10.3, and can be temporarily raised up to 11.5 if contamination is found.

Finally, it is a good practice to wash the spirulina several times right after the harvest, to get rid of excess nutrients and lower the pH so it’s more suited for human consumption.

Although anabaena and spirulina are both classified as cyanobacteria, they are very different from each other. While Anabaena is capable of producing neurotoxins, spirulina is not only edible but also highly nutritious.

It is unfortunate that the lack of basic understanding has brought certain researchers to confuse spirulina with Anabaena and other types of toxic cyanobacteria, because of their visual similarity.

The wild samples of spirulina which were found in certain lakes and rivers in Africa and were claimed to be toxic were in fact a mixture of spirulina and a mixture of cyanobacteria such as anabaena and others, creating the assumption that spirulina itself can be toxic for human consumption. This was later found to be a false claim.

Indeed, it is not advisable to consume spirulina from natural sources without first looking at it in under a microscope lense, as there is no other way to identify what species are present in the water.

To avoid such contaminations, spirulina cultivators are advised to maintain high pH, and increase it even more when any other organisms appear in the water.

Unfortunately no. Since spirulina is a live cyanobacteria, you need a live mother culture that can grow and multiply as single celled organisms do.

The drying process, whether done naturally under the sun or using an industrial spray drier, kills any living bacteria, including the algae itself.