This is the question we get asked most, and getting it wrong is expensive either way.
What a softener does
It exchanges calcium and magnesium — the minerals behind scale, spotting and a water heater that dies years early. It treats every tap in the house. Think of it as a plumbing-protection device rather than a drinking-water one.
What reverse osmosis does
It sits at the kitchen sink and pushes water through a membrane fine enough to take out dissolved solids the whole-home system is not built to catch. Much finer filtration, one tap, and it is the part you actually taste.
The unit we install is the HW800 AlkaPro: seven stages, an 800 GPD membrane, and an alkaline remineralizer that puts minerals back afterwards — which is the difference between purified water that tastes flat and water people will actually drink. It is tankless, so it makes water on demand instead of eating your cupboard.
Why you generally want both
A softener will not improve what your water tastes like. An RO unit will not stop your water heater scaling up. They solve different problems and neither substitutes for the other.
When you might not need both
If your only complaint is taste and the test comes back at the soft end, say so. We would rather sell you the right half than the whole thing and have you tell your neighbors we oversold you.