increasing hardness

[nplummer at duke_edu]

The water from our well is extremely soft and acidic.  According to the
County Health department, it has a pH of 6.1 and total hardness of 19
mg/l.  Tetra test kits give roughly the same result (pH 6, gH <2, kH <2).
It is wonderful for orchids and carnivorous plants, but it corrodes
our copper pipes.  To prevent blue deposits in the bathtub, I run the
water for the house through an acid neutralizing system, which is
basically a big tank of calcite.  That gives me a pH of 6.8-7.0, gH <4, kH
<2.  Hmm, shouldn't the calcite raise the kH as well as the gH?

My previous experience with the yeast-CO2 method was in a town with hard
water, so I'm thinking I should bump up the kH of my water before I start
adding CO2 now.  I'd also like sufficient calcium for shrimp to survive.
Can I get away with just adding sodium bicarbonate, or do I need to add
some calcium and magnesium, too?

Nick
-------------------
Nicholas Plummer
nplummer at duke_edu
http://www.duke.edu/~nplummer/