Leaking fresh water tank

[amweath]

Being as how the fresh water tank was empty, I thought I'd sanitize
it using the method described in the Bluebird manual. On entering the
coach the next morning I found the carpet on the right side of the bed
wet.Am I in big trouble? I've removed the mattress and the plywood
covering. It doesn't look like any of the plumbing is leaking. The next
step is to try and lift the tank out (it has been drained).Has anyone
done this? I'm wondering how much of the bed frame has to be taken
apart. Can these tanks be patched?

Art Weatherly
Riverside Ca
'85 PT 36.