I've noticed that everyone seems to be running open top barrels for their biofilter, meaning, the media is exposed to light.
Correct me if I am wrong, but should not the media be in total darkness 100% of the time?
IDK, JKB. All media biofilters I am aware of are all open to light. Even my Fluidized Sand Bed filters use clear plastic. I think it is more important to have dissolved oxygen.
In a "green water" system, algae is the substrate for bacteria, light is essential for the algae.
