"Wayne.B" wrote in message
...
On Sun, 15 Jul 2007 17:48:23 -0400, "Roger Long"
wrote:

Is putting powerful and dangerous biocides in the tank and pulling the
sludge out with the filters the only option? (In between major fuel
polishing episodes.)

I've had good luck with Biobor. If it's not toxic, it won't
accomplish much. Be prepared to change your filters a little more
often for awhile. I loaded up my tanks with the recommended shock
dosage last year and was changing filters every 50 to 100 gallons for
awhile. Now I've just run through over 1400 gallons in the last month
with only one change.

Every 50 to 100 gallons? Good gravy! I haven't used 20 gallons in 6 years.
This is going to take a while...