How low is the water level?
Suds, the proper "high" level is anywhere from the second to the top row of tub holes. There is a hex nut adjuster on the water level switch, but before you mess with it, check the air dome hose going from the tub (back right corner) up to the water level switch. Make sure there is no crud or leaks in the hose. (or any build-up at the tub opening). If the water level needs to be tweeked, just barely move the hex nut. Have you booted your Neptune yet??
Bobby in Boston