Growing Spirulina at home – my new algae project


In this post you will see how I am growing Spirulina at home step by step.

As I have written before on this blog, Spirulina is considered one of the most healthy foods in the world.

Read this blogpost for the amazing benefits of spirulina supplements

While the corona virus have caused food hoarding lots of places, I have been more concerned with food safety than before.

I am not considering myself as a doomsday prepper, but its interesting to have the option to create my own food..

I have read instructions and information on how to grow, but I have not found a simple to follow step by step instruction yet.

That is also a part of the reason I make this tutorial.

I will provide you the exact:

  • costs
  • tools
  • starter kit
  • medium and growth mixing
  • Growing strategy
  • Lightning strategy

This is the starter kit I have used for this project:

Starter algae culture

Grow medium

In this post I will share my Spirulina growing experiment as I am progressing.

Here are the cost and equipment I have had growing my culture:

50 Liter aquarium

2 aquarium pump

2 aquarium heater

TOTAL COST: 50$ (used aquarium + pumps/heaters, bought private)

1 starter kit

starter culture ( $ 53)

starter growth medium ( $ 8)

growth medium for 6 months ( $ 32)

Total cost including freight costs $106 (healthalgae)

1 digital ph measurement tool

cost $6 (aliexpress)

This gives a total project cost of 162 dollars.

This can seem expensive, but keep in mind this is the startup cost and 6 months of growth. When growing I can harvest every day and only have the nutrition costs of 32 dollars. You will then have fresh high quality micro-algae each day .

Ordering the Spirulina starter kit

Monday 16.03

I ordered my Spirulina starter kit from healthalgae. Since the company is located in my neighbor country Sweden, it was the most logic choice for me.

It is a major benefit to have the live culture to travel as short as possible, and if you are ordering a algae starter kit I recommend to find a supplier close to where you live.

When I contacted Healthalgae I also got an excellent customer service.

Here is the starter kit recommendation I got:

A 500 ml +10 L medium and a extra 80 L medium would work for you and a 10 liter cultivation over 2 months. We also have a 720 L medium that would last you for circa 6 months of 10-30 L cultivation. The accompanying manual will give you more info on how to feed your culture with other nutrients too. We ship everywhere.

The suggested products:

Starter kit received

Wednesday 18.03

I picked up my starter culture and growth medium at my local post office today.

Living Spirulina culture
Spirulina culture

First I opened the culture to let it get some air, and I plan to let it settle for two days in room temperature before I mix it with water.

Growing Spirulina at home
Water, Spirulina culture, and growth medium

I have made ready a 1 liter water/nutrition mix with 21 grams of nutrition for the 1/2 liter of Spirulina culture. I have not had access to distilled water, so I used tap water with a small amount of c vitamin added.

The main challenge for the water mix, is that chloride often is added to water. Chloride will kill algae, and are not god to have in the mix.

I found the tip to use boiled water and c vitamin from a YouTube video. From the Healthalgae kit it was recommend to let the water stay out open 1 day before use to let the chloride out of the water, so I also did that..

Ready to start growing Spirulina algae in my aquarium

Friday 20.03.2020

I waited two days as as per the instruction to mix the algae culture with the nutrient. I used one liter water/nutrient mix for the half liter of algae culture

grow Spirulina at home
Ready to start growing

The mix of water/nutrition and Spirulina was added to the aquarium, and a small portion of Spirolina culture was kept in the bottle to build a backup culture.

The backup culture

The backup culture was put in a open bottle with a equal amount of nutrition/water added. Then I put the backup culture bottle in the window to grow on its own.

This was the steps I took today

  • Mixing of 1/2 liter live Spirulina culture and 1 liter of water/nutrition mix.
  • Mixing of a small backup culture on a separate bottle
  • Made ready 1 liter of water/nutition mix to use for growing the culture larger. 21 grams of nutrition was used for 1 liter of water mix.

It is important that the water and nutrition mixes well. In the instructions it says to stir for 20 minutes. I found that it was smart to mix the water and nutrition in a 1 1/2 liter bottle and just let it stay on the bottle until needed. This way the nutrient have a very long time to dissolve in the water.

2 day of growing Spirulina

Saturday 21.03.2020

Today I started blowing air into the culture.

The pump was giving air into the aquarium and everything looked perfect…

But then I had my first minor setback, the pump stopped working ave about 10 hours of use. It was a used pump that was included with the aquarium, so it was not a big problem. I also got a submersible pump with the aquarium, but I need to have more medium before I can start using it.. I ordered a new pump. The air pumping is not essential in the beginning as I understands, but when the culture grows, the air pumping will help on the production.

First week summary

Now I have started to get the culture growing. Generally I just mix up one liter of water and nutrition every other day now.

For lightning I use two fluorescent tubes that came with the aquarium top.

I try to have the lights on about 50% of the day, and of during night time.

Since the pump stopped working, I just let the culture have som quiet time without air pumping until I get the new pump in a day or two.

I will move on to weekly updates on the post form now.

1 day week two update

Monday 27.3.2020

Got my new pump in the mail yesterday. Started pumping air into the culture. I am using one gas stone and one open hose.

I bought the Eheim pump with two outlets, you can find this pump on Amazon also:

I also have submersible pump ready to use then there is enough medium.

A a total of 4 liters of water/nutrient mix are in the aquarium right now.

I am still growing in room temperature (20-22 degree Celsius).

The plan is to start using the aquarium heater when there is enough aof culture in the aquarium.

This is how my Spirulina looks after one week of growing
Spirulina backup culture bottle
Backup algaes

I have doubled the amount of backup culture adding the same medium as I use on the main culture. The backup looks thick and good.

Week 3 update

Friday 3.4.2020

The culture is growing fine and I am now filling one liter of water/nutrient per day. I have made a simple system where I use 3 bottles for the water/nutrient mix. I fill all bottles with 1 liter of water and leave them open to let the chloride damp of for two days. After I add nutrient to the bottle I put on a screw can and shake the bottle. I usually do the nutrient mixing in the morning and pouring it into the spirulina culture in the night.

I have bought two new backup culture containers in glass.

Voss mineral water was perfect to use for this use. Voss is actually regular tap water from Norway, in nice glass bottles. It probably the most expensive tap water in the world, but still the cheapest 800ml aquarium to be found :). I payed around $3,5 for each of the bottles.

Backup bottle with gas stone in Voss bottle

I have one backup culture with air injection and one without. For the one without air injection, I have in my widow and just shirr a couple of times a day.

Week 4 update


One liter of water/nutrients added per week. Received my digital PH meter and did a PH check to see if the spirulina had the right PH grade to have a good growth.

I got PH 10.05 on my digital PH meter

The PH level seems to be good for growing. The best growth PH level is between 9.5 and 10.5 according to the Healthalgae manual.

Week 5 update – Turning on the heat

Monday 27.4.2020

The amount of spirulina is now 20 liters in the aquarium.

I have decided to stop adding nutrition and water, in order to increase the culture thickness.

The amount of medium is now high enough in the aquarium to include a heater.

Temp before heating:

Temp after heating

Week 6 update – waiting of increased density

Monday 04.5.2020

The culture have been left alone this week in order to get denser before harvesting. I have kept the heat on about 30 degrees and had lights and bobbles on in periods.

Week 7 update – Ready for first harvest

Friday 14.5.2020

The spirulina cuture is now dense and ready for harvest.

I have take out about 800 millilitre in a bottle for filtering, and filled 1 liter of nutrient into the main culture in the aquarium.

Spirulina ready for harvest

The harvest was not much, after the filtering I had a teaspoon of spirulina.

I will let it grow for one more week and do a new harvest.

I will continue this post as the growing continues, so make sure you bookmark it:)

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By Beejay

Bjojo runs the Vegan MeatLab blog. He is also doing experiments on Spirulina growing and micro greens. The long-term plan for the Vegan MeatLab project is to come up with the ultimate vegan hamburger based on natural vegan food.

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