cultivation instructions
I would like to give you here a small instruction for the best success of your algae cultivation.
Please remove the bag with the algae immediately after receipt of the delivery, fill it into a larger container, place it in a warm, bright place without direct sunlight and make sure that the algae get enough air, e.g. by opening the lid. It is also a good idea to shake the algae up at least twice a day by carefully tilting the container. The more often you mix up the algae the better it is.
After about 24 hours the algae should have recovered from the stress of transport (darkness and no air exchange). After that, it is advisable to dilute the algae to about twice the volume. To dilute it, put a part of the enclosed powder in water, which should be at room temperature. You can preferably use tap water (if the water is chlorinated, leave it open for at least one day before giving it to the nutrients), but you can also use still mineral water or distilled water. The powder contains the nutrients that the algae need to grow, and it is designed for a dosage of 20g per liter. For the first dilution of the culture you can for example prepare a 50ml nutrient medium, and add 1g powder to 50ml water. The powder must be stirred well, but will still not dissolve completely, which is not a problem. Leave the culture medium for a while after stirring (e.g. 1h) and make sure that it has the same temperature as the algae when adding it to the culture.
The container for the culture should be transparent and have a large opening to allow plenty of light and air to reach the algae. It is best to cover the vessel to protect the culture from contamination. A glass vessel is more suitable than a plastic one because plastic can release harmful substances to the algae and thus later on to you, especially under sunlight.
After diluting, you can carefully start to accustom the algae to direct sunlight, because with more light they grow much faster. It should be noted, however, that too much light can kill the culture. Therefore, it is advantageous not to expose the algae to the sun at midday and only for a short time in the beginning. For example, 30 minutes of sunlight and 30 minutes of shade are suitable for repeated exposure. In addition, it should be noted that the sun can strongly heat up the algae culture. The optimal growth temperature is slightly above 30°C, but the culture can die at temperatures above 40°C. On the other hand, with colder temperatures the metabolism of the algae reduces. This makes the culture more sensitive. Over longer periods under e.g. 20°C this can lead also to the death of the culture.
If everything goes well, you can see that air bubbles form when the algae are exposed to bright light. This is a sign that photosynthesis is in full swing and the algae are multiplying. These bubbles also cause the algae to be driven to the surface of the vessel, which in the long run leads to the top layer of algae drying out. Therefore, it is still necessary to ensure that the algae are mixed. The rising, bubble formation, or sinking of the algae also provides information about the condition of the culture. If bubbles form and the algae rise, everything is fine, and they grow. If the algae sink, they are not actively engaged in photosynthesis. This can have various causes: Too dark, too bright, too warm, too cold, too little, too many nutrients, or a too-high pH.
The pH is a parameter that should be checked from time to time, for example, with universal indicator test strips from the pharmacy. Remove a small amount of the algae with a spoon or similar, dip the strip into it, compare the color, and do not return the sample volume back into the culture. Spirulina lives in an alkaline environment, which makes the penetration of harmful microbes almost impossible. The nutrient powder is designed to have a pH of 9 in the specified concentration. During growth, this pH is further increased by the algae until they stop growing at a pH of 12. In this case, the culture can be diluted with a nutrient medium or the pH can be lowered by additional aeration. Please be careful with bringing too much air into the culture. The carbon dioxide in the air is diluting into the water and reducing the pH. If too much air is getting into the culture it will die because of a too-small pH. This is especially the case for a thin culture or if it gets not much light.
The culture can then continue to grow until it has regained a deep green/blueish coloration. After that, it can be further diluted or harvested in parts. To observe the growth of the culture and to have an idea of when it can be harvested, the depth of visibility is a good indication. For this purpose, a rod can be equipped with a white object, e.g. a cap. This is then dipped into the culture until the white object is no longer visible. This is the depth of view. The culture should not be diluted below 5cm, otherwise, it becomes too susceptible to stress. If the depth of vision is less than 1cm, growth slows down, and the algae can be harvested. For harvesting, a fine-mesh sieve or coffee filter can be used, and the algae can be eaten pure or added to other foods.
With an aquarium heater and artificial lighting, the growth can be accelerated, but they are usually not necessary for the survival of the culture. It is also advisable to divide the culture as soon as possible and store a small amount of the algae in a container at room temperature, air, and without direct lighting, as a rescue in case the main culture dies.
When the nutrient powder sent with the culture is used up, you can either buy it from me on eBay or Etsy, from another spirulina store, or you can mix it yourself. There is a recipe on the FAQ site with ingredients that are all available on amazon or on your local specialist shop. If you have any questions or suggestions, please feel free to contact me.