MJB wrote:
I originally went to RO because my tap water has a pH of about 7.6. I made
the switch before I put in the CO2. Never considered going back to tap
water.

pH stable claims to not contain phosphates. I do have a history of
higher-than-one-would-expect phosphates. I'll have to do some tests on my
reconstituted RO water and see if that could be the source.


With the addition of CO2 if your tap PH is 7.6 and your KH is around 3
(guessing) and you set the PH controller around 6.6 to 6.8 you would
have 15-25 ppm of CO2 which is what some of the pro's around here have
recommended for planted tanks in the past.

If you want to see a good table for the PH/KH/CO2 relationship have a
look at http://www.thekrib.com/Plants/CO2/kh-ph-co2-chart.html

Hope this helps,
Ron