A 1' deep bucket will also do it.
Warranty 7 years
Motor HP .6
Discharge 1½"
Water Start 12"
Water Stop 3½"
Current Start 25 amps
Current Running 8.6 amps
Max Head 21½ '
Capacity 60 GPM @ 10'
Weight 19 lbs
Height 11"
You could use the 5 gal. bucket and a 10' vertical hose to check the capacity. It should fill or empty the bucket in 5 seconds.
"the level drops right back to where it started from." I guess you've already tested the capacity. . .
While the thing still works measure the voltage and current into the running motor, at whatever head you will be using this pump, so you have info for troubleshooting after your 7 years are up.
BTW, this pump/motor combo is 40% efficient at converting elec. power into water lifting power.