No, the softener, if it is set up with sodium chloride, as they usually are, will substitute sodium ions for both calcium and magnesium ions in the water. Since hardness means the amount of calcium and magnesium in the water, the softener reduces the hardness. Too much sodium is hard on plants.If I am not mistaken, the main thing that happens in your home water softener is that calcium is converted to magnesium? Both of these are useful in plant tank if they are in normal ranges. And when it comes to plants and fish both calcium and magnesium are both factors in water hardness, so despite what your hardness meter might say, your hardness really doesnt change, just shift from Ca to Mg. Can anyone verify this?
My story is, I've been using softened water for years without any ill effect to plants (at least that was directly caused by the softened water). Or shrimp. Or fish.-Does anybody have any 'soft water' stories?