Plumbing question

[Seasidenj]

I have 2 frag tanks I'm plumbing together both are 90 gallon tanks.Each tank has 2 3/4 returns and 2 one inch drains.Im guessing 1 is a emergency Drain .I'm going with one sump and 1 pump Varios 8.My drains I'm going with 1.5 inch pvc t ing them together. For my returns should I go with 1 1/4 or 1 inch PVC for my returns off my pump.REMEMBER IM FEEDING 4 3/4 RETURNS.Thank you

 

[Dr. Phil]

Hi! If it were me and I were splitting one pump that many times, I would go with the largest pipe that would fit the output of the pump. Then you have the ability to add gate valves to the smaller return pipes to reduce the amount of flow as needed.