I talked with the Culligan folks, and their system will use potassium just as easily as sodium. Problem is it costs three times as much!
I've never been one for paying the ridiculous prices for bottled water. And I'm not about to start. Drinking the water here hasn't done me any harm yet. Even with the bacteria problem. But there is another reason we have to get that fixed.
As for my plants, well, they've been in this water for nine months now. The sword plants, Ludwigia, and dwarf swords have all done very well, but my Alternanthera never really thrived after we moved here, and the Nymphaeas shriveled up and died after a few weeks in this water. If Vals can take the sodium, fine for me. I've been wanting to get some for this tank for a while anyway.
I do have a way that I can get water that has not gone through the softener. I just have to get it from the spigot in the basement. Fill up one or two 5 gallon jugs, let them sit overnight, and mix them with the water from the tap. That should help.
But hopefully the township will finally get around to bringing municipal water through. I'm hoping that's not more than two years off.