ZWF14791W Rinse Water level?

I live in a very soft water level, and despite reducing the washing powder to half a scoop, the machine fails to rinse adequately, i find myself filling on the service cycle and running the service cycle twice jut to rinse the load... i am wondering is it possible to adjust the rinse water level setting on the machine permanently through the menu? its a decent machine, washes excellently its only downfall is the rinsing..