New to this forum. Way behnd the curve. Reading to catch up.

Question. The plas thin film vertical growth system containing membrane. . .The agal cells do not tend to lodge on this surface? They do not bind to it at any stage in there life cycle? Are there any that would bind to some film?

Consider: A running film system in conjunction with verticality for photons and timed exposure, neutrient exposure timing & concentration, maturation to stauration for maximum yield?  Cleaning a surface as opposed to a filtering process.

As I said, way behind the curve.

I'll be lurking as I'm a layman to the field(s) of study.

 Pete,

That film system will probably be too expensive for production use.  You might use it in a lab for some tests.

Some algae do form sticky clumps and will stick to any surface. There has been some success in introducing glass beads into the PBR flow. The beads knock the algae off the sides and back into the stream.