I watched without sound, so sorry if these were answered.
Why not just cut a hole in the 5gal bucket and stick the nozzle in there?
I'm assuming the pump couldn't handle pulling material from down in the hole? Otherwise it looked like it was running really well.
Looked like a lot of water flowing over the sides instead of down the sluice. What was up with that?
Each and every 90 degree angle in pipes that turn costs you up to 7% of your psi/gpm in resistance. Convalution is not the solution.John