Water detector paste- maybe

[Techno]

Found this while shopping for something else.
Heres a clip of the description.

Here's an easy way to determine water or gasoline levels in tanks. Simply use a brush or your finger tip to apply a thin layer of paste to a gauging tape or stick. Insert the tape or stick into your tank for 30 seconds. Remove the tape or stick—the paste will change color (red for water finder; white for gasoline finder) to indicate your fluid level. Furnished in a 3-oz. jar.

Maybe it will take longer than 30 sec. but may be worth it for some of you humid lovers.
The jar is $4.44
I figure you drop a line or whatever in and if it comes out red then you have water in the fuel tank.
http://www.mcmaster.com/
page 2040
part # 89775a15
Forgot to mention this stuff is for checking tank levels for bulk tanks. Might work for a water tester though.

[ShorePounder]

Yup, name of the stuff is called COLOR-CUT. Works well. We've use it to gauge water in large tanks, and we've used it at gas stations were we thought we'd gotten bad gas in our work trucks.

It will turn color wen the slightest bit of water hits it. If they leave any out over night, the dew will make it turn. I think it comes in a tube like RTV