For return pump, will T-off to FR, the rest to chiller, then to main tank. The flow rate to main tank will be around 2000L or less after head loss. I estimated about 8X turn over.
As for wave maker, don't think can operate at full power, definably will create sand storm within the 2 ft cube, will tune controller for adjustments.
Alternatively, I will go for bare bottom for maximum wave motion , will see how it go.