I had the tank cleaned but discovered that it still has contamination. There is no way to access it other than the siphon tube and the float level fitting. At this point I'm considering filling it with water and cutting an access hole in the top. It appears that there is a baffel about 12" from the siphon tube and tank filler tube which is the area I'm considering cutting. The tank is .090 aluminum. Anyone have knowledge on the tank on a 1985 SeaRay 230 cuddy?