I didn't remove the tank. What I meant is draining all the fuel will effectively get any water out of the tank. There was some crud in there.
The guage was down to where the light was on. I thought at the time maybe it had two or three gallons left. Since then I have found the low fuel light comes on early.
If I had to do it again I would run it down further of course, but I would still be prepared to handle more fuel. Just get plenty of cans or whatever right there and have a plan to handle it.