i always thought if you turned the flow down with just a tapyou get the cycling effect with the pump and thats what knackersthe pressure switch.cant you have some kind of loop system like i use on my backpacksso not all of the water goes to the brush but goes back to the tankif at times you want less flow
must be a way of making an adjustable return back to yourtank so you can have a varied flow without hampering the pump