The machine determines water by sensor, some have complained that it doesn't "completely cover the clothes" or doesn't put enough water in the tub for their tastes. In the manual it explains that this is because it is part of the "High Efficiency" function of the machine. I have not had a problem with the amount of water the machine decides to put in the tub. My clothes have come out just fine. If you feel it needs to completely cover the wash, there is a "Deep Water" function on the machine that will do just that.