I bought a 1 HP Harbor Freight 69300 dirty water pump to drain a green pool but it won't turn on at low water levels: https://c2.staticflickr.com/6/5458/17045005639_a6ee73cc98_c.jpg
Even with the obnoxious float switch manually set to permanent on, the pump stops pumping with plenty of dirty water left to pump out: https://c4.staticflickr.com/8/7699/17230627861_6245741c9b_c.jpg
I'm currently shoveling the water into a garbage can and then pumping it out from the garbage can: https://c1.staticflickr.com/9/8811/17023759327_4ff798a613_c.jpg
But, pumping at 50 gallons per minute, I have to constantly run to the GCFI and pull the plug to shut it off before the garbage can runs dry: https://c4.staticflickr.com/8/7642/17043416128_f6c37715ab_c.jpg
Currently I have a 2-inch pool vacuum hose connected to the 1.5-inch outlet (female NPT thread) in the steel body of the pump: https://c1.staticflickr.com/9/8805/17023759957_35d602a39d_z.jpg
But, I'd like to see if I can jury rig *something* (a rubber hose perhaps?) to go on the *underside* unthreaded inlet of the pump: https://c2.staticflickr.com/6/5443/16610976993_e8ed88636b_z.jpg
What could I shove into that inlet which will allow the pump to go shallower than the three or four or even five inches it seems to currently stop at?
I have a few 1.5-inch NPT fittings which go on the *outlet* of the stainless steel body: https://c4.staticflickr.com/8/7644/17023759797_46bc0500f9_z.jpg
The specs for the pump "say" it drains down to 1-3/8 inches: http://www.harborfreight.com/1-hp-stainless-steel-submersible-dirty-water-pump-with-tethered-float-2910-gph-69300.html
But, the owners manual says it stops at 3 inches (which it seems to do): http://manuals.harborfreight.com/manuals/69000-69999/69300.pdf
Have you ever dealt with a dirty water pump that just wouldn't drain the last few inches? Is there a simple solution?