TreeClimber said:I have seen a difference when using well water that has gone through a water softener. I now get my water for seedlings from a point before it goes through the softener. I think the salts have negative effects.
I would think it's possible it would have a negative effect especially if there's a significant amount still in the water (which I thought there wasn't supposed to be but we once had a water softener that was adjusted wrongly and the water tasted salty until the technician finally checked and fixed it).
Anyway, salts are the reason seed starting media should have little or no fertilizer, because fertilizers are salts and salts have a negative effect on germination (and plants in general) if concentrated enough.