KCl vs K2SO4

From Paul S.
      >>  Why would you prefer Cl- to SO4-- in the tank?  The plants
can use sulphur in fair quantities, and I don't think they need
all that much chlorine.<<

I use KCl because I have a life time supply (from hardware store - muriate
of potash). I don't have a conventient supply of the other, but could get it
from a chemical supply house if necessary. I never thought it was important.
Although I agree that the S is more useful than Cl, my tap water already has
25ppm S. And I had been adding Epsom salts for the Mg and some extra S.

Do you think that continuing to adding a ppm or so of Cl together with
weekly or biweekly 25 % water changes could be bad? Assuming no Cloride
assimilation, what would be the concentration at the end of a few years? 

Neil Frank, TAG editor    Aquatic Gardeners Association    Raleigh, NC USA