Re: CO2 and buffering

> From: Matt Rhoten <mrhoten at oz_net>
> >> add sodium bicarbonate to keep my carbonate hardness up and my pH
> >> stable
> > I don't think this is a good idea.  Sodium bicarbonate will also raise
> > the pH, not stabilize it.  Again, DIY CO2 is your best bet IMHO.
> Then what is the recommended way to raise carbonate hardness? 

Sodium bicarbonate or calcium carbonate IS the recommended way.  Yes,
they will raise the pH to the mid to high 7s and CO2 is then used to
bring it back down to 6.8 or 7.0.  If you used a buffer that did not
raise the pH, it would be difficult to get a neutral pH with useful
amounts of CO2.

> I'm not
> likely to inject CO2 with a carbonate hardness of roughly 30ppm
> (that's around 1.7dKH). 

Right, 3.5 to 5 dKH is a good range.