The tank was cleaned, blasted, and repaired before it was reinstalled back when I did the CVZ resto. I had one area that I had to cut out and weld in new, it was just pitted and soft. It happened in an area where the foam got saturated and was in contact with the side of the tank. Fortunately the inside looked better than the outside, I used a sewer inspection camera to give it a good look around. The amount of water I collected from the filter seemed to be plenty, but I also ran through probably 200 gallons of fuel last season, 70-80 was at Red Wing meet alone. So as a percentage its not very high of water to fuel, I was just concerned where does it come from. The filler is new and the ring is in place and pliable. Could spray get in the vents, there are two on the Z? Could come from the gas station? Marinas probably have better quality fuel, but I generally fill at the local gas station.