Do you drink the well water?If yes your plant will drink it just fine.
+rep for you buddy.
This is good advice. Not all tapwater is suitable for growing. If it has a lot of dissolved solids it can cause all sorts of issues. I personally use r/o water and my plants love it!
That's true, they do waste a lot of water. If your tapwater sucks like mine does, there really aren't many options. One thing that isn't mentioned much is mixing r/o with tapwater. This way you can bring your water into the ppm range you prefer and you don't have to use as much r/o water. For a long time I used the grocery store self serve water machines. Those are reverse osmosis units and the water costs from $.25-$.40. Pretty cheap, but it's a pain in the ass lugging 5 gallon jugs to the store a couple of times a week.
Not necessarily true about rainwater. While a lot of rainwater has an ideal pH and a small amount of Nitrates, some of it has an extremely low pH and is polluted with all kinds of nasty stuff I wouldn't want to put in my garden.
Chlorine isn't a big deal because it evaporates out of water relatively quickly if left in an open container. Chloramine, on the other hand, does not evaporate and there are conflicting reports on the affect it has on beneficial microbes in soil. Most tapwater is just fine for growing. A small percentage of tapwater has an extreme pH (usually on the high end of the chart) and is very hard. Dissolved solids can interfere with nutrient uptake and lock out other nutrients. These effects are not typically seen after 1 or 2 waterings but can cause a cumulative buildup in the soil, wreaking havoc with nutrient uptake. pH is easily adjusted but dissolved solids can only be removed by reverse osmosis, distillation, or Deionization. Best of luck and happy growing.