Synchronizing drain to return

[David Abbott]

I have a 150g DT. My drain is 1", I have 2 1000gph Hydor DC pumps in my sump for my return both 1". With the pumps at the lowest setting and the MAIN DRAIN WIDE OPEN it is completely silent, as soon as I increase the pumps to the next lowest setting the secondary drain starts gurgling, on the next setting (maybe 50%) the water level goes directly to the emergency drain. Is this as much flow as I can expect??? Does the height of the secondary drain make a difference??? I can raise my emergency drain 1/2" and my secondary drain up 1" will raising the 2nd allow me to increase flow of my pumps?????

 

[FFFishy]

I'm not a plumbing or physics expert, but . . .
Gravity flow of water through a 1 inch pipe would max-out at about 950 Gallons per Hour. The "1000gph" rating for your pumps is probably best-case and might be a bit overstated. The only way to know your true flow rate would be to properly install accurate flow meters. Having said all that, I do not believe you will be able to run both of your pumps at max with only a single 1 inch drain. I believe that a single 1.5 inch drain would allow you to run both pumps at max.

 

[Tonycass12]

I'm not a plumbing or physics expert, but . . .
Gravity flow of water through a 1 inch pipe would max-out at about 950 Gallons per Hour. The "1000gph" rating for your pumps is probably best-case and might be a bit overstated. The only way to know your true flow rate would be to properly install accurate flow meters. Having said all that, I do not believe you will be able to run both of your pumps at max with only a single 1 inch drain. I believe that a single 1.5 inch drain would allow you to run both pumps at max.

This is right your pumps are moving too much water for your drain setup to handle at anything but the minimum. Luckily turnover through your sump does not need to be very high. Add some powerheads in the tank or loose one of the return pumps.