Quote Originally Posted by famousdavis View Post
While I haven't been using the waterfall, I've never had the pH be stable for three days in a row.
A waterfall aerates the water increasing the rate of carbon dioxide outgassing which causes the pH to rise. No mystery here. Lowering the TA level reduces the over-carbonation of the pool so reduces the rate of pH rise, but reducing aeration sources also helps. The SWCG also aerates the water with its hydrogen gas bubbles and may also have some chlorine outgassing, both of which cause the pH to rise, if the pipe run between the SWCG and the pool is relatively short.