Re: [A/S] hot air bubbles

[Jerry Flanders <jflanders2@xxxxxxxx>]

When you pump air into the tank to put the water under pressure, some of
the air actually dissolves in the water. 

After the water has been sitting in contact with pressurised air long
enough for this to occur, you can see this air come back out of solution by
drawing a glass of it and letting it stand. Air bubbles will form on the
glass walls.

Cold water can retain more dissolved air than hot water, so the effect in
the glass will be even more promounced if the water is warm or hot. You may
not see many bubbles form at all if the water is very cold.

It appears that you are dissolving so much air in the water while in the
pressure tank that it is actually forming bubbles as it comes back out of
solution in the hot water tank. Reducing the temp of the HW might help, or
reducing the air pressure you use to pressurize it.

The first TT we bought was a '67 Norris that used an air-pressurized water
tank. The air dissolving all the time was a real nuisance. Also, as it
dissolved the pressure was reduced and so I needed to pump more. I finally
rigged up an automatic air pump to keep it pressurized, but never solved
the air-bubbles-in-the-drinking-water problem.

The above reasoning is also probably why free-swimming fish seem to prefer
cooler water - more oxygen in it.

Jerry  W4UK (retired Chemist)