I personally don't know if high iron is bad for pepper plants, but I would guess that the high levels of sodium in softened water would be detrimental to your plants. Too much fertilizer use, especially in containers, can cause salts used in the fertilizer to accumulate in the soil and lock-out nutrient absorption by the plant. Using softened water would basically be putting salts into your containers and over time salts would build up and possibly harm your plants.
Are you removing the iron from the water by means of a water softener alone, or do you have an iron filter/water softener 2 phase system? If you are running an iron filter first, you should be able to take water from after(downstream of) the iron filter but before (upstream of) the softener. If you are only using a water softener, you probably have a lower iron concentration, and you may be fine to just feed them straight well water.
You should see if you can find the water analysis of your well, then you would know the exact ppms of iron and other minerals you are dealing with.
Are you removing the iron from the water by means of a water softener alone, or do you have an iron filter/water softener 2 phase system? If you are running an iron filter first, you should be able to take water from after(downstream of) the iron filter but before (upstream of) the softener. If you are only using a water softener, you probably have a lower iron concentration, and you may be fine to just feed them straight well water.
You should see if you can find the water analysis of your well, then you would know the exact ppms of iron and other minerals you are dealing with.