K2SO4 and MgSO4

[Ric Otte <ric at otte_ucsc.edu>]

Hi,

I've been using K2SO4 in my tank, but am about to run out of it.  Since
I've found local sources for my other chemicals (Phosphate, KNO3, and
Iron), I'd like to find a way to get something similar to K2SO4 locally.
I am wondering if the 'important' ingredient in K2SO4 is the SO4?  If
it is the SO4, I was wondering if I could use epsom salts (which is
basically MgSO40 instead of K2SO4.  If so, that would be both cheap and
local, which I like.  If I need K2SO4, does anyone know of a commonly
available version (like stump remover for KNO3)?  Thanks,

Ric