Having somewhat hard water, though depending on what makes up its hardness, can help in washing FB prints. If the water is high in carbonate, you may want to compare the residual thiosulfate levels, after washing in your hard water, and after washing in distilled water. You may be pleasantly surprised to find no difference, and maybe even better results with your well water. On the other hand, if your well water is heavy with some other less helpful minerals or heavy metals, you could be worse off with it, but I suspect you wouldn't have found it so tasty.
Originally Posted by fretlessdavis
In any case, using a hypo clearing agent with FB should help no matter what water you use, being even more important when using distilled water.