"Dave M. Picklyk" wrote in message
...
I wouldn't buffer the water with baking soda (unless you have acidic water
already---but 7.6 should drop to about 6.8 or so which is fine for most
fish)--if you do that, you cannot accurately measure C02 with KH and PH
readings without strictly letting your water be carbonate buffered
(natural
buffering capacity of the water). Also, some natural water supplies have
high phosphate content, which invalidates any calculations for C02
readings
including C02 test kits.

Just a thought,
Dave.


Actually, you can buffer your water with baking soda all you want and still
be able to accurately gauge CO2 with pH and KH measurements. Sodium
Bicarbonate would not violate the condition of the water being
carbonate-buffered.
__
Alex