It sounds like there's a lot of variation in what works for different people. I'm on 'city water' that still requires a water softener (yeah, we have to pay for the city water AND still had to purchase a water softener AND the more expensive potassium chloride because they don't allow regular salt)
...I'm concerned about the salts affecting my seedlings because I don't have a great access point before the softener to get my water in the winter. I do have several seedlings started--not intentionally, they had germinated in the seed pod--and I've been using the softened water and they seem to be doing great so far.
For these early stages, I have the 3 eager-beaver, sprouted-in-the-seedpod seedlings in K-cups filled with soil. Once I begin to germinate my other seeds sometime early next year, I plan to still use the K-cups to grow them, initially. It might seem crazy to others and completely not worth the added effort, but, for now, it makes sense to me.
I figure that if a seed doesn't germinate, atleast I haven't wasted much space/soil/etc. on it. Space is definitely at a premium here. Starting them in the small K-cups might also make it easier to bottom-water earlier on, too, but I'm not sure. In the end, it makes me feel good to have an additional use for the K-cups.
As a side note, we're considering ditching K-cups until they come out with recyclable K-cups that will fit the older generations of machines. So far, Yogi tea is the only one that I've seen make recyclable K-cups for the older generation(s) of single-serve machines (mine is a CuisinArt that brews K-cups but also has a re-usable single-serve filter/cup). Yogi tea is good, but sometimes I just have to have my coffee.
