[untamed]

Originally Posted by StirCrazy

I ran at 7.9 on my SPS tank and it was fine. I wouldn't worry about trying to raise it unless you are having problems and you know its the PH.

Steve

This is true, there is nothing really bad about pH 7.9. A bit higher is better...but hard to achieve. One thing you will surely see if you track your pH over 24 hours is that it goes way up in the daylight, and drops overnight. Minimizing that daily fluctuation would be a better goal than trying to move from a 7.9 avg to an 8.1 avg.

I've found it possible to reduce the nightly low by dripping Kalk only during dark hours. In fact, I can tell when my Kalk reactor needs new Kalk because the nightly pH low becomes distinctly lower when that happens. (Which happens like clockwork every 14 days)

Finally, rather than attempt to "blow off" CO2, I would recommend adding a second stage to your Ca reactor. Stage 1 of my reactor runs at pH 6.5, but the effluent is up to pH7.2 by the time it runs through my second stage.

One of the challenges with "blowing off" CO2 is that our homes tend to have a higher CO2 concentration than outdoors. Even outdoors, we've generally raised the CO2 concentration over the entire planet which is a contributing factor in the acidification of our oceans and decline in coral reef health.