Question on the use of potassium chloride as a substitute for potassium sulphate. Chuck Gadd's calculator lists potassium chloride, % breakdown, etc. Wondered if anyone has used it in their aquarium? My only concern with potassium sulphate is perhaps the negative effects of sulphates in the aquarium. I was wondering if any info was available on its usuage, pros and cons, etc. Also, where to purchase, and if there is a trade name for this chemical? Does it dissole readily in the aquarium? Didn't see it on Greg's website.