water doesn't seep into your gas tank. it is in the gasoline and condenses when the time is right to form water crystals. a common cure is to go to the autu store tell him your story and he will tell you the best brand to solve your problem
The only way to know for sure if a person has water in the gas tank is to drain the tank. Usually a car will sputter and die if there is water in the tank.
remove the fuel tank and drain the water
What will happen if water gets inside gas tank
skipping stall no start
bubbles on top of gas in tank
Water is heavier than gasoline, it will pool at the lowest point of the fuel tank.
Remove the tank from the car.
Yes, water is heavier than gas.
Have you tried using gas line antifreeze? That will help to remove some of the water in the gas. The best way to make certain all the water is out of the tank is to siphon the gas out, let the tank air out and re-fill the tank with gas from a station you know does not have water in the gas.
Look and see where it is leaking from.