[Gordon Watson]

What is the best flow-control device at the pole end? My cheap, 1/4" blue-and-white plastic ball control valve is a little stiff and awkward.

Thanks,
Gordon 

[MartinB]

Valves at the brush end will always put a backpressure onto the pump and cause pressure switch problems.

Take a look at the new Varistream from Williamson Pumps on http://www.williamsonpumps.co.uk/varistreamspec.pdf.

This unit controls the speed of the pump, and also will automatically compensate for the height the brush is at, giving a constant control of the flow.