yes. add muriatic as recommended by someone else on the list, dilute and drip it in
gradually. yes, baking soda dissociates to CO2 and H2O in the presents of acid.
Actually goldfish and koi do well in hard water, but lakes are naturally soft, they
just arent "softened". soft water is stripped of any buffering capacity, Ca+ and
Mg+. that means the pH will swing wildly and that makes the fish suffer. in
addition softening strips out chloride ions which are necessary to gill function,
breathing. and softening adds scads of Na+ which can sometimes be so high it is
toxic. http://tinyurl.com/5fsbu9

calcium and magnesium stabilize the HCO3- or carbonate hardness. it wont raise a
high pH. OTOH, you are tyring to get the calcium out of the pond because there is a
huge excess. it isnt a buffered calcium tho, which is what the problem is. the
water out of the well at my mothers ponds is so full of calcium that the water is
milky when the ponds are refilled after cleaning. but there is a buffer that
prevents the calcium from locking up the chloride ions. INgrid

On Sat, 28 Jun 2008 14:03:02 +1000, "David Hare-Scott" wrote:
OK but you do this by dilution or by adding acid
Yes in the presence of acid. Is that what you mean?
Why? What is wrong with soft water in a pond? What benefit is hard water for
pond life?

Dolomite is roughly calcium magnesium carbonate, that will tend to raise pH,
not what is required in this case.