Tom Barr writes: <snip>> Get your KH up to about 3-6 and the Ph to stay in the 6.6-7.0 > range. Is that possible? In my experience a KH of 5 draws up the pH above 7.0. Or are you counting on the CO2 to push it back down? Is the a chart on the net that shows the lowest achieveable pH at give alkalinities without CO2 injection? Bob Dixon