Greetings, for several years now I have been using a product called Ethanol Defense after getting good reviews from a friend. I purchased it from amazon. The first time I ordered it, I also purchased some 1/2 ounce glass bottles to dispense it. 1/2 ounce treats 5 gallons and the filled bottles make it very convenient to add without the hassle of needing to measure. Just thought I would throw this out there.
Richard