I think I'm going to use softened well water as a last resort. I don't have a water softener installed yet, and my original plan was to bypass the softener for tank water. I'm going to stick with this plan for now, and if it proves to be unmanageable, then I'll switch to softened water. Lastly, if that still doesn't work, then I'll switch to RO and install all of the nonsense that goes along with that whole mess =)Depending on what the results are you may find the softened well water is the lesser of two evils. I have well water and it's very rich in iron, so using it directly was out of the question. But it does vary a great deal depending on your location.
And I ran my tank for quite a while with softened well water. While not ideal, you can still have a great tank. It does limit some choices of plants, but sounds like you are only going to be keeping a small number of species. If so, just might take some time to determine which ones like the soup you are serving.
And keep in mind well water can vary a bit. My KH would fluctuate seasonally, going from about 12 to 18.
For the time being, I'm just going to try to work with what I have.
And holy smokes on that KH. What kind of ph does a KH of 18 come in at? That's nuts!