keving,
I have about 240 gallons delivered every 8 months into a 275-gallon tank. I think that's about the same usage as yours. I had been lugging 5 gallon jerry cans and pouring them into a 55-gallon drum, but that got old pretty quick. The local jobber will deliver 200 gallons or more at a time. My tank is exposed to the weather and I have had water condense in it, so to every delivery I add an 8-oz. bottle of FPPF Fuel Power and a dash of FPPF Killem biocide. That keeps the fuel in good shape. Every 2 weeks I draw a small sample at the drain cock and check for contamination. No problem as a result of the FPPF brew.
Cheers, Mark