So I finally got to my built-in gas tank (had to remove my center console to get to the hatch). I intend to drain the tank and give it a good cleaning. I noticed that there is a corrosive looking white cake-up around two of the tube fittings going in/out of the tank. I wish I had a pic, but it looks just like the stuff you'll see on old battery terminals, just alot more of it. What is this and is this indicative of a greater problem? I've had a lot of fuel issues in the past with my boat, and wanted to service my entire fuel system before I hit the river this winter, starting with the tank itself. Thanks for everyone's help.