Meanwhile… after scaling up in bottles and now a bigger container (IKEA… offcourse) I have about 20l of Spirulina saturated water. The bigger open watersurface and fine spread bubbles in the container raised the moist level in my growbox significantly.. I placed a glass plate on top with just a 1cm gap to let O2 out. Still…. I can’t close the door completly so there is some aeration in there and avoid condenswater leaking out. Since I don’t see any salts depositing on the inside of the box I assume the water vapor is not that salty… I have some room plants here who’d prefer a more moisty air so maybe I can move the bigger container out of the growbox next to these plants
Also, it’s about time to start doing some harvesting! Or so I thought… The water looked nice and dark green but when I checked with a (diy) sechi stick it appeared that the density was only about 0.35g/l in the Ikeabox. In the glas bottle it was about 0.5g/l so I decided to try and harvest from the bottle wich is only 1l. Must be said that after moving to the ikeacontainer the average temperature in the growbox went down to 24°C and probably the light dosage is not so efficiënt as with the glass bottles.
Tried out 3 filtermedia, non really worked that well for this small amount;
- linnen cheesecloth = small amount of Spirulina ‘stuck’ in the clothfibers
- lab filterpaper = clogged up, tears apart when trying to push through, scraping off spirulina afterwards not without also scraping off paperfibres
- coffeefilter = works best but very slow, small amount of spirulina scraped off after pouring through about 200ml. Water ‘exiting’ the filter had almost no Spirulina left in there