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Re: potassium levels/water softener

Hello Ron,

You are on the track of a very good solution! If I remember correctly,
you ahave water of about 330 ppm hardness. 

This high hardness is possible only if one has some extra CO2 dissolved
in the water, to form calcium bicarbonate [Ca(HCO3)2], which is
reasonably soluble. Calcium carbonate [CaCO3] is soluble only to the
extend of some 20 ppm (at room temperature).

So, when you are warming the water, (say, from 10 °C to 20 °C) you are
DECREASING the solubility of CO2 in the water and therefore the amount
of calcium bicarbonate that is being formed. The equilibrium will swing
to the carbonate, which is insoluble, and it will precipitate out.

This process is slow, but after a time you will notice a grayish-white
precipitate on the bottom of your barrel. Not only you will have
tempered water, but it will be a bit softer. Within reason, the longer
you age it, the softer it will get. 

I have a bit harder water (370 ppm) and I can get up to 80 ppm reduction
in hardness just by aging my water for about 2 weeks. Do NOT remove the
calcium carbonate precipitate on the bottom -- it serves as a nucleation
site and speeds up the process of precipitation.
Good luck.

Best,

George




>     Thanks to everyone that took the trouble to help with my tenuous  > grasp of chemistry. Since our new softened water heater outflow will  > be much too high in potassium or sodium to use in my tanks, in order to do water changes
at the right temperature I'm going to have to heat unsoftened water in
barrels before adding it to my tanks :-(. This is my punishment for
years of
self satisfied smugness about not having to deal with chlorine or
chloromine
when doing water changes...

    Short of installing another water heater fed with hard well water
for
use in my tanks, am I missing an obvious solution?  I've bypassed the
softener with the cold water supply to the fishroom, but the hot water
is
treated.  What does everyone else with domestic water softeners do for
water
changes?



Trying to choose between blue or white barrels...<g>

Ron Barter
Perth, Ontario