Greyhawk Fresh Water Overflow

[MrJackSprat]

On two occasions we have witnessed a "full" fresh water tank "spilling in transit" upon travel - loosing nearly 1/4 water upon arrival. I have ready multiple threads here regarding this issue for both TT & MH. Some even have witnessed a siphoning action further draining the tank.

I read a simple solution was to extend the overflow hose(s) above the fresh water tank and loop around, but our tank is flush with the floor boards and not an option. The other suggestion was to install valves to the existing hose(s), but another thing to remember (forget) when you prep before/setup after. Plus you need to crawl/reach under the MH (something that wife isn't too fond of if camping without hubby). Third was just to plug the hoses, but could burst the tank upon fill pressure or usage vacuum.

Any ideas on a simple/clean solution? A thought was to install an additional outside valve like the black low point drain on our Greyhawk. Could operate without diving under MH and clearly see setting upon prep/setup.