When I was digging my my big pond, I picked up some dented 100 gallon fuel tanks used on the sides of big rigs, mounted them on a trailer and put a 12 volt diesel fuel pump on it. I was filling it up at least once a week, sometimes twice a week.
Since then, I found that it wasn't worth the time and hassle to fill up 180 gallons of fuel for what I was using. I just use 2 yellow five gallon jugs and keep the tanks topped off. I never use enough fuel in a day to empty a fuel tank, usually it's not enough to even use a quarter of a tank. When I fill up my truck, I fill up the two jugs and then pour them into whatever tractor I'm planning on using.
Since the modern nozzles are so bad, I've been buying junk from Amazon with the hope of finding one that actually works. My issue with them is that they all break at the threads when tightening them. I've added the air opening so the fuel flows better, but I'm still struggling with a good tube to put into the tank. Usually what I do is remove the tube and just pour it in without the tube. This works fine for most of my tractors, except for my small tractor. Since it only holds something like ten gallons, and I usually only put in 3 or 4 gallons at a time, it's not been too bad to deal with the Amazon failures.
On the failures for replacement fill tubs, never buy the flexible ones. They where the worse!!!
Since it's getting closer to batwing mowing season, I'm going to have to look again from a better filler tube for my cans. I mostly need them for my gasoline cans. I have one that's really good that's 20 years old. I put it on the gas can that I'm using, but I know it will fail eventually and then I'll be stuck with the junk I've been buying to try and replace it.