[hockey nut]

ok..... looking at the mak 4 box , and if grade three was good to me , my calculations are 450gph at 14 foot head. Or something like that. max feet is 22 for a mak 4. On the box it is in meters and litres per minute. So worse case here, lets say 5 meters is close to 14 feet x 32 litre per minute as according to the box. so 60 min x 32 = 1920 ltr per hr, divide x 4 for gallons = 480 gph. again this is a rough estamate. HTH