I'll second the PowerService. Sometimes I'll empty my 300 gallon tank 3 or 4 times a year, and sometimes only once or twice. I always just add one bottle of the PowerService diesel addative I buy at my local Rural King. I've never had any problem in years of doing so. Apparently my fuel must be pretty clean from the Co-Op where I have it delivered. I generally have my fuel filters last several years before they need to be changed and I never get any sediment in my viewable bowls.
Ha! I after reading the posts on the leach fields on septic tanks, I had to make sure that I spelled bowl right. Think about it... /forums/images/graemlins/grin.gif