Hello ,
I carry 2 , 7 gallon plastic fuel tanks in truck due to the small fuel on board tank and have found alge growing in one of the tanks . I now have some concern about the main tank and i do have the Kennedy baldwin fuel filter installed but would like to know what product treatment can i use that would address alge in the tank . I do keep the main tank as full as possible due to the cold weather changes here always going thru the dew point and really dont expect the main tank to have any problem but i do believe in preventive maintance . Rich

Many of the readily available diesel fuel treatments contain a biocide. Read the back lable to find one that does and add some to your tank, and to the two 7 gallon tanks. This will kill the algae. You can strain the goopy stuff out of the 7's after a couple of days. As for your truck fuel tank, keep an eye out for signs of clogging fuel filters.
Probably won't be a problem if you haven't poured any fuel in from the 7's. Regular use of treatment, especially in warmer weather wil help prevent the growth of algea in the fuel. It needs water and warmth to grow.