From Marie's and JimK's experience may be something to the calcium comment from JacksMagic, even though hard to explain. Time to order more HEDP - any preferences between KemTek vs. Pink Stuff? KemTek on sale on Amazon, but PinkStuff worked for JimK. Where do you get calcium chloride? Is that the product Pool Stores sell as Calcium Hardness Increaser - if I decide to try to up CH to around 200. Thanks for any thoughts or comments.