Yes - I have 4 tetras that are doing quite nicely. I have no desire to harm them! What I did, on advice from the good folks who read my first post, was to do a series of small exchanges over a number of days to get the tank back to just well water, and doing it slowly ensured that the tetras would handle the change to their environment, which they did just fine.
Today I took the kids to the pet store and we picked out 2 guppies and 2 glow fish - bright red and bright orange and the guppies also happen to be yellow and orange, all very colorful! - and as I write my tank water is dripping into their container at a rate of about 1 1/2 drops/second and so far so good! This was much easier to set up than I feared. I got air tubing, a gang valve, and suction cups to hold the tubing in place. The gang valve is usually for regulating air flow from an air pump, but it works just as well in reverse controlling the drip. So I cut a short piece of tubing, attached it the output side of the valve, and secured it in the tank with a suction cup. Then I cut another piece of tubing, attached it to what would normally be the input side of the valve, got a suction cup ready, started a siphon, closed the valve part way to slow it down to a drip, and secured it with the suction cup in the container with the new fish (which were swimming in enough of the water from the bag to give them some room). The container is sitting in a bucket to prevent the water from overflowing onto the floor. So far the fish seem to be fine. The drip's been dripping for about an hour, and the only problem is that it may not be done before my son's bedtime! (The tank is in his room.)
So I'm really hoping that the guppies are OK and they survive my well water pH. Wish us luck!
Thanks again to everyone for all of your great suggestions!
akg