Bleach is good but do not use the cheep stuff. Bleach is only good if it is plain bleach Clorox Brand. Imports have soap and other things in them Clorox is pure bleach as long as it has no other marking on the lable like Downey fresh or some thing.So a gallon of bleack is what $2.50 so get a couple and shock the tank with both gallons and fill the tank all the way up. Bleach kills everything thats why they give it to junkies to kill the AIDS virus on the needle they use. But Check it out Clorox is pure bleach and fit for water I use a 1/4 cup in the tank about every two months and do the shock once a year,did I say i
pump it through all the
lines also. You can save it and use it to defunk
fenders or bilges what ever. It kills mold also. CLOROX import brands British bleach has soaps in it. They do make a Pure Bleach but I don''t have the name of the British brand.