The only time I have ever noticed bubbles in my purified water; in the absence of any detergent, is following a period of immobilisation, when the water that is in the hose has sat there for a number of days- say on a Monday morning after the weekends inactivity. At such times, until the hose water has been completely flushed out, you'll sometimes find a preponderance of the little fellas accompanying the water in the scrubbing and rinsing process.
It never seems to persist longer than a couple of minutes. But, today, after fitting a new micro bore hose, I've had bubbles all day long. I can't say that I have ever noticed this accruing with any of the other new hoses that I have fitted in the past.
Has anyone else experience the same phenomenon, and if so, how long did it take for its cessation.
Thanks Nick