>>>>If I
>>>>leave the old, wet leaves in the pot overnight (per normal sometimes)
>>>>and prepare a new cup in the morning by adding new leaves to the old
>>>>with hot water, the water seems to turn into a clear thick slimy liquid.
>>>>

I have not had this happen to the extent you describe, but I *have* had teas
that left a perceptible film on the pot's interior. I commonly just rinse my
pots out with very hot water, rub the sides with my fingers, and that's
usually enough. But when I get a tea like this, I use dish soap or detergent.

For me, it always had to do with specific teas. Not that they tasted bad at
all; just some characteristic of the tea. It didn't take all night for the
film to form, either.

Three ideas:

1) Try saving your spent leaves overnight as usual, and in the morning NOT
adding new leaves, but just rebrewing the old ones...and see what happens.
Maybe there's some reaction between the new leaves and old?

2) Perhaps your new environment has some unusually vigorous airborne bacteria
that go to work on your spent tea leaves overnight. I never found wet leaves
to be an ideal growth medium, but had a heckuva time with this issue when I
used to do homebrewing.

3) Send Uncle Lee packing. ;-)

Joe