Another culture of blackworms is running for two weeks now, and the worms evidently multiply, even at 17 C degrees. It is built from an I*ea storage box with a tray inside. The tray is perforated to allow a pipe to pass (right). A sponge filter with pump takes water from the bottom compartment through the perforation. Water returns from the tray to the bottom via the handle in the tray, which is partly blocked with filter foam. My estimate is that this system contains 20 liter of unchlorinated tap water, and that I will be able to feed at least five tanks from it. The worms live on an around dice of filter sponge (large pores). Food: pellets with a high percentage of Spirulina. Water changes: none yet, but I plan partial changes at 15 day intervals. A third system is already in preparation, more news soon I hope….