A Spin Filter system for the study of algal interactions.

In Spin Filter flasks interacting populations of algae can be grown in such a way that they are kept separate spatially but remain in close contact chemically. The rotating filter unit of the flasks is a solution to the clogging problem. In experiments with this system Chlamydomonas globosa was always inhibited slightly by Chlorococcum ellipsoideum, but Chlorococcum was only inhibited by Chlamydomonas when the latter had an initial advantage.