Well, I've cut back on my nannochloropsis cultures from 150g to about 20g now as I've switch to using spirulina powder from Brine Shrimp Direct and putting it in the blender with some water and blending it for two minutes. The spirulina is MUCH more nutritious than nanno.
I used to grow four other cultures of phyto but found keeping them to be to much of a PITA as they required VERY clean situations and were easily contaminated by airborne spores.
I stupidly sealed the container so that nothing could get in except the air from the air pump, not realizing I was still introducing the spores through the pump air. Duhh!
The nanno however, I grow in a 20g rubbermaid container meant for storing things I think. It's low and rectangular so I use spiral lights over it for growth. I find as long as I don't take out more than half of the culture at any time, I don't get crashes.
I clean out the container about once a month at a time when the culture is down to about half full. I pour the nanno through a 65 micron mesh net (again from BSD) to remove larger particles that have accumulated, (and bugs that get in and drown) and pour back into the cleaned out container.
