I agree with Bob. From my experience trying to change the pH of an
aquarium, I've learned that it matters what else is in the water that
might act as a buffer to changing the pH level.

Dave

On May 9, 12:07*pm, zxcvbob > wrote:
> Ray West wrote:
> > Can anyone tell me how much citric acid is needed to lower the Ph of a
> > given ammount of water from Ph7 to Ph4 or 5. A search of the web has
> > revealed nothing.
> > ** Posted fromhttp://www.teranews.com**
>
> You question is not answerable. *It depends on what is dissolved in the
> water. *(if you have distilled water, just the CO2 from the air is
> enough to drive the pH down to about 6.)
>
> Bob