Keeping fresh water tank clean

[duckdave]

I want to thank Interblog, and other contributors, for their extensive efforts to educate the rest of us oblivious campers about the science of disinfection of our water. Although IBs needs for water purification greatly exceeded the norm (she's taking lake water and making drinking water—most of us just want to disinfect our tanks and water lines so our already "potable" water stays that way), the discussion about the great variety of Clorox products, and the fact that only 2 or 3 are suitable for drinking water was very enlightening. I learned A LOT! Thanks to all!

The tip about looking in the hardware department to find the correct Clorox for water treatment was spot on. My Ace Hardware had both the recommended "concentrated regular bleach" and the "germicidal bleach concentrated" in stock. You have to take your time to find all of the words on the label, they don't appear together. So like IBs discovery that her months-long search for the correct product, was found in the (what was it, the Walmart Paint Department?), with that direction I found it in ACE Hardware.

Also valuable in this discussion were directions about how much to use, how to distribute, how long to expose, and how to flush...I learned I was using the wrong Clorox, I was using to much, I was leaving it in to long, and not flushing it out enough.

Right now, my AS trailer (1978) is pumping grey-colored water from the "fresh" water tank. My preliminary assessment is: I used the wrong bleach, I left in it in the lines too long, and the bleach damaged the impellers of my 10-yo water pump, causing it to shed particles to discolor the water. Interested in comments!

[InterBlog]

Well, I thought this discussion had concluded, but then we on the Gulf Coast had Hurricane Laura and Hurricane Beta close behind it.

And in response to flooding and disruption of water and wastewater utilities, our state environmental regulator began publicizing information on how to safely bleach water. That was a source I had not previously consulted.

Aside from the ominous warning at the bottom of their page, namely "Using any brand of bleach not manufactured to ANSI/NSF Standard 60 for public water systems is a violation of the Public Drinking Water Rules", they provided a link to an NSF site where, theoretically, people could look up whether or not a particular bleach met the standard.

Except it doesn't work - it lists manufacturers, not sources attainable to consumers. (I emailed the regulator about that).

Anyway, it also says, "The label, Material Safety Data Sheet [(SDS)], or packaging will state that the product meets ANSI/NSF Standard 60."

The hell it will. I went over my Clorox Germicidal bottle with a fine-toothed comb and there was no such assurance of technical conformance. Then I downloaded the SDS and it wasn't there either.

So - back to the drawing board - I emailed Clorox with a different spin on my original question, and they responded promptly with the confirmation that Clorox Germicidal is manufactured to that standard: