Water Change Pearls

["Tom Wood" <tomwood2 at flash_net>]

I suppose it depends on the water supply system. Where I live, the water
comes out of the tap at a pH of 9.8 because all CO2 has been intentionally
driven out at the water plant. 'They' don't want acidic water in the supply
pipes because it is bad for the pipes made of metal. Let that same water sit
out for a while, and as it takes on CO2 from the atmosphere the pH
stabilizes at about 7.6. So I doubt any bubbles that form in the tank after
a water change, in my locale, are CO2. Once I was made aware of the
mechanics of this, I threw away all the pH adjusting chemicals. Try it
yourself on your own tapwater.

TW