Re do the pick up tube so it goes completely down to the bottom. The end of the pick up should have small notches cut into the end so even if it touching bottom, it is not dead ended. I use the Hypro jet agitation nozzles fitted with DCER-6 discs. These are ceramic discs instead of the usual plastic or steel, so no rust and a long wear life. Those are mounted on a tee at the end of a down pipe bulk headed into the tank. The agitation line is tapped off of the high pressure line feeding the hose reel. Do not take the agitation from the bypass off of the pressure regulator if you are running a plunger or diaphragm pump. You also do not do this to a roller pump either.
They who can give up essential liberty to obtain a little temporary safety, deserve neither liberty nor safety.
Benjamin Franklin 1775
Sell not virtue to purchase wealth, nor Liberty to purchase power.
Benjamin Franklin Poor Richard's Almanac1738