"Racf" wrote in message
...

I thought I remembered this.....and I tripped over a possibility. It
really has to do with your dissolved C02 levels in your tank and how it
behaves with CaCO3 (Calcium Carbonate). To make a long guess
short.......If your dosing right after a water change...if your CO2
level drops CaCO3 will/could come out of solution and manifest itself as
milky white pooh until it can dissolved back into solution....which can
be a little while. Does your change water contain elevated amounts of
dissolved CO2? Mine does here in MN....

That's a very interesting train of thought.

My tank has quite high disolved CO2 (around 25ppm due to injection) whereas
the tap water is very low (around 3ppm).

I normally balance alkalinity between new/tank water, but the disolved CO2
will be quite different. Not enough to cause much of a hiccup with the pH
due to the dilution and effect of the CO2 controller, but possibly enough to
give rise to a chemical reaction causing the tank to cloud for a while.

Thanks for the post. Experimentation to follow :-)


Graham.