Loosing fresh water

[Mike61]

When I fill the fresh water tank, I notice that the overflow tube continues to flow. I have not paid much attention to this until I started to travel. After 300 miles, a Navy shower and doing dishes one time, I noticed that our water fresh water level was down to 1/3 tank. When I refilled the tank, I again noticed that the overflow tube continued to drain water for a long time. I finally folded the tube in two and ducked taped it to stop the constant flow of water out of the overflow tube. What can I do to prevent this from happening again?

[ependydad]

From reading on here- add a quarter turn ball valve to the tube. Open it when you start to fill and close it when full.