coralreefer
No Pistons
Mike in the summer I've gone 6 hours a couple times with no problems.Really, 8 hours of no water movement you feel most corals and fish could survive? If so, then it would be wasted money for these automatic battery systems.
Luckily I think 3 hours is the longest we've been without in the winter. With temps outside in the mid teens...IIRC...tank temps dropped a degree or two in that time. Almost hooked up the generator that day but the power came on.
BTW we do have access to a generator and have used it to run pumps and heaters if we have an extended outage.