Pump flow rates for waterfall ATS

[atoll]

I have tried to find recommended flow rates of pumps equired for waterfall ATS's but have found little. If there are some suggestions on here can somebody point me in the direction please? Perhaps a rough guide of gallons per hour per 1" of screen or whatever etc might be a good idea if there is no guide already available. Thanks.

[SantaMonica]

Water flow is at least 35 gph per inch of width of screen [60 lph per cm], even iff one sided or horizontal. The pump itself will need to be more to allow for losses.