Reducing gph for return pump

[jason604]

Originally Posted by sphelps

If your pump is rated at 600GPH it won't actually pump that much given there is head pressure losses from both static head and pipe friction losses. In many cases you only end up with half the rated flow, there are online calculators you can use to get better idea.

A valve on the output is fine, it just adds to the head pressure, no different than adding more height.

After testing the pump is too strong at 4 feet head so I decided to split the return line back to sump and now it's running perfectly