The VERY first thing I did two yrs ago when I bought the boat was to pump the fuel out and put a 6X9 access port in the middle of it. Scrubbed the tank out and checked pickup tube and tank. Filtered the fuel (was only 10gal) and put back into the tank. The previous owner stated the fuel was only 8 mo old. The tank wasn't that bad and being aluminum, had some corrosion on the bottom. I now physically know the condition of the tank. And, I'm going to replace it next winter (33 ys old). I hate it when fuel starts leaking out over the cabin sole......Also use Stanadyne treatment with every fill up...