Thanks, fish lover. The tank seems to have stabilized at 7.2 (pH) and
80KH. I'm still doing readings every week, sometimes more often. As
long as it stays stable, I'm not concerned about raising or lowing the
amounts, but if for any reason it becomes unstable, I'll keep your
suggestion about the shells (I've also read this elsewhere, and it
seems to be one of the more stable approaches - compared to adding
chemicals / powders, which I'd prefer to avoid).

Thanks,

Liz


fish lover wrote:

You may want to put in some shells in the tank. That may keep the PH
to 7.5. They will acting as buffer and you don't have to worry about
ph crush. You may have to add some more shells once a year or so
because they just 'melt' away slowly.

I learned my lesson the harrd way. I was trying to lower the PH in my
tank and it kept bouncing back. Finally some people told me about the
shells I kept in the tank. I took them out and the PH came down
without any big effort.