Poor Circulation with New Pump

[gedmonds]

My original pump motor died. Before it passed on, it produced 18 psi and had enough power to run my spa jets and produce a good flow over the water feature.

My replacement pump had the same specs. However, the jets do not run with the same power and the overflow is running low. The installer said my filter was dirty. I cleaned it with no better performance. The installer said a reducer for my Krawler was restricting flow. I removed it with no better performance. He now is saying I need to replace my grids in the DE filter. Before I do that, can anybody offer a better, more likely guess since the old motor had no problem circulating the water with the existing grids?

[Me...]

You would need to post model numbers of old and new pumps.