I will be beginning my pond project this summer providing I find a very large water pump very cheap. I have located a great deal-a 6 month old 6000 gallon per hour external water pump for $160 plus shipping. Providing that I have large enough overflows on the tank, could a 6000 gph external water pump be fitted to a 55 gallon sump? Would the water be too turbulent in the sump? If my 1000 gallon tank has a medium/large bioload, would around 40 gallons of pot scrubbies in the sump be sufficient for biomaterial? If not how much bio material (gallons of pot scrubbies) will I need? Also, if I Have a single overflow on the tank, then how large ( in diameter) should it be? Thank you very much!
