I would be afraid to depend upon water power to turn one of those rotating gizmos. Just about anything would stop one from rotating and once it does it will dry out and never turn.
Originally Posted By: Rainman
I beg to differ about "wasting" oxygenation power. Using that flow to turn an RBC would INCREASE all gas transfers.
I also wonder what makes you think an RBC is easy to stop. Rock solid reliability and capacity is what makes them the single most common filter used in "old school" (read; reliable)densly stocked aquacultuce systems.
Rainman is right. RBC's are actually quite reliable. My axle which is PVC inside PVC and under water, has no danger of it not moving again once it stops. I can assure you there is virtually no friction and it creates flow and oxygenation as it turns.
As far as the plates drying out, in a worst case scenario less than half of the plates would dry out, but if you're worth your salt as a RAS operator you are constantly on guard for power outages and wouldn't let that happen. The big commerical systems have alarms and automatic back up.
Just like NASA you need a back up for everything, regardless of what kind of system you use as you really are dealing with an artificial life support system. I have a spare for all my pumps just in case.
I presently have battery operated pump to take over my clarifier pump that also turns my RBC if I have a power outage. (Only one small 60 watt pump to power the whole system for about $4.00 per month in utilities.) I will in the future get a back up system that will automatically covert my 110 volt pump to a 12 volt DC for up to 12 hours on just one battery. If I put two in a series I can run twice as long and so on.
If pigs could fly bacon would be harder to come by and there would be a lot of damaged trees.
