I simplified the plumbing near the pre-filter today as I had planned. I tossed away about $60 in plumbing parts including a check valve I couldn’t get unscrewed from its threaded piping.
While at the store I finally found a 2″ pipe cutter. The kind that spins around and has a cutting wheel and tightens like a vise. The one in the picture is similar but my cutting wheel is stationary and the rotator wheel moves with the screw handle. This tool makes wonderfully straight cuts with no more effort than using a hack saw. Sometimes the right tool just makes things easier.
I would also recommend to folks building a pond under 2000 gallons to use 1 1/2 inch pipe. Easier to cut and cheaper for specialty items like valves. Most pumps are cheaper too in the 1.5 opening size.