Harvesting Spirulina alge


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  1. Introduction
  2. List of materials
  3. Harvesting
  4. Refill

1. Introduction
This is a smal manual on harvesting spirulina. If you like to remain growing spirulina then keep 1/2 or 1/3 of the spirulina, and add nutrients water.

2. List of materials

-A sieve cloth, or if you don’t have one a clean dishcloth
-A bigger bowl to catch the remaining water
-Clips to keep the cloth on its a place
-A glass or smaller jar
-A glass plate
-A spoon

3. Harvesting

  1. Prepare the bigger bucket as on the photo.
  2. Pour the algae water over the cloth, I like to use a smaller bottel or glass to prevent any leaking.
  3. Wait until the water is gone trough the cloth, check if the water in the bowl is clean.
  4. Use the spoon to scrape the algae carefully from the cloth.
  5. Keep the algae on a clean plate to dry.

4. Refill

If you like to continue growing spirulina simply add nutrients liquid to the saved spirulina.

For One liter of nutrients liquid:
1 L of water, No tap water! (Filtered water, Distilled water or rain water)
16 gr / L sodium bicarbonate
1 gr /L sea salt
2 gr / L potassium nitrate
0,5 gr / L potassium sulphate
0,1 gr / L ammonium phosphate
0,1 gr / L magnesium sulphate few drops of an iron solution and lime

Place the tank back in light and add airflow.


Thanks for sharing this.
I saw Maria @mboto hosted some workshops on this in Ghent the last weeks, have you been to any of them them? Maybe there’s additional tips from that practice which can be included or used to cross-check information?

Later update: just saw your other post on coloring based on the workshops, so question answered :slight_smile:


Still if you miss information: Let me know and Ill try to answer and add to the forum! :slight_smile:


What happens after that you place the tank in the light? Do you have photos of the spirulina grown in lab?


We do! Even some videos. First one I can find is here: https://www.facebook.com/ReaGentBiolab/photos/a.1502889510030056.1073741828.1488980081420999/1997761890542813/?type=3&theater