i'm certain this might cause some argument,but i was reading somewhere about how to clean the clear 5 gallon water jugs we all use.i think on melev's sight.he was using bleach.maybe mix a water and bleach solution and move the water with a powerhead for awhile.maybe overnight or something.then rinse several times and leave it out in the sun for awhile.the bleach i would think would kill any bacteria or anything.the main thing is to make sure its rinsed very well.cause we all know chlorine is very harmful to our systems.