The Spirulina tank is still building momentum. This is batch #3.
This time, I’m taking all the precautions. I sterilized a different tank, got a new air pump and hose and sterilized that with alcohol. I even sterilized the heater.
The water that I add for the nutrient mix is mains tap water with the water ager/dechlorinator added and this batch started off with a fresh 3 litre batch from Ken at Spirulina Grow Co.
It should be totally Chlorella free (Chlorella contamination killed the last 2 batches).
The tank is getting about 4 hours of direct Sunlight per day and is in general daylight for the rest the tank has an aquarium grow light in the lid that is on 24 hours a day along with the air pump and heater (set at 30°C).
It got to a max of 34 on the last hot day we had. Eve had a few chilly nights but the heaters been on all of the time and the tank is on a Styrofoam base and has Styrofoam at its back and the side away from the sun. These sheets provide insulation as well as bounce more light onto the culture.
I mix the nutrient mix in a dedicated bottles that contained the Spirulina culture when it arrived so there can be no contamination there.
The powdered nutrients don’t dissolve cometely, there is some kind of filler in there. I mix, shake well, shake well after an hour or so then let it settle for a couple of hours. Then it is strained through a coffee filter.
So far, I’ve expanded the 3 litres of culture to approximately 10 litres.
If this doesn’t work, I’m going to quit the Spirulina experiment. This is the 3rd try and I reckon that’ll be enough. I’m concerned by the amount of light coloured stuff that comes to the surface when I stir deep down. It’s green but maybe it’s too light in colour?
We’re not sure what killed the first batch, it was going well, then suddenly tanked (pun intended 😁). Spirulina batch #2 was killed off by Chlorella contamination. Chlorella is a microscopic algae that loves the conditions that Spirulina thrives in. That batch was grown on rainwater and the Chlorella must have been in there from the start.
Ken has been great so far with advice and supplying replacement batches so I hope that this batch works. Spirulina is a true superfood and I reckon it should be part of everybody’s home food growing efforts.