melev

Good stuff. This is VERY common! Everyone that I have coached on water quality and other tank issues gets a lecture about starting at the wall. Some listen, some don't. And public utiliies LIE about what's in the water all the time. You cannot trust their reports. And as you stated, this issue can be seasonal. I tested my source water twice a month and plotted radical changes in "polutants". Many aquarium salts can have ammonia in them too. Hobbyists assume that what they are buying off the shelf is safe...

I had a recent issue with water out of my RODI coming out with .5ppm ammonia. Something we really need to keep an eye on...