< Back How many hand washings will a full tank provide? Angeles® Portable Hot Water Sinks come with a pump system that provides up to a ˝ gallon of water per minute. Water usage levels depend on the length of time spent hand-washing. If each child washed hands for the Center for Disease Control (CDC)-recommended full 30 seconds, and the water was run at the full ˝-gallon level for the duration of those 30 seconds, you’d expect to get about 20 hand-washings per tank. However, more hand washings can usually be expected if the water flow is conserved or turned off during soaping and turned on again just before rinsing. Typically, one full tank of water will last the day.