[Silencer]

Does the light effect both types of bacteria or only one? For example if you ran the tubing coil on the outside of a pvc tube exposed to light, but the bioball reaction chamber was inside the opaque pvc, would this be ok? Or would the light harm the coil bacteria too that remove oxygen? Or is it the other way around maybe, and the bioball chamber could be exposed to light but the coil should be hidden.

The other question is what is the radio of tube inner diameter to required coil length? For a larger tank you could run multiple small coils or a few coils with larger tubing and I'm curious which would be more compact and easy to deal with (since with multiple small coils you have multiple connections and more hassle/complexity).