The first time we attempted to harvest was a disappointment, as we couldn’t harvest anything… Turned out the problem wasn’t just the bad quality of the harvesting sieve that came with the kit, our culture had to be < 1 cm (Secchi disk) to harvest!
The second time, our culture was ready to harvest and we managed to collect some to taste and observe under the microscope.
lastly, we tested the pump to suck culture rich media from container, pump it up to the filter where Spirulina is collected and the media is then dripped back into the container to be reused.
Here, we also tested 2 different filters to see what works best. The 10 micrometer paper filters collect the most culture, but are too slow for the pump, yet the paper coffee filters collect less culture but much faster. We realized this works to our advantage as the unfiltered culture that goes back to the container with the media is necessary for the next harvest.