I'm not worried about breeding yet, but some of the fish are susceptible to lateral line erosion in hard water. I'm not sure of my water hardness, I should look up the Baltimore City water report and see if they track that. Plants are a no go for me, I rarely keep lights on my tanks, and don't do well with them even when I do.
To Frank's point, if I were doing small tanks, I'd be ok if I were using small tanks, but I have 3 groups of fish in 2 different QT tanks for a total of 80 gallons, so spending $8-$40 per week isn't practical for me.
I might consider just having a 40 gallon used for softening water, either using peat with a powerhead, or as a reservoir for RO water. Rain water collection isn't practical until we move to our 'forever home' as I'd want the storage containers indoors.
Anyone have a RO unit for sale? I tried to win the new unit at the BFD raffle, but was unsuccessful.