The short answer
Without a main-line install, a portable softener on a hose connection or an electronic descaler that clips to a pipe are the realistic options.
What you can install
| Option | Install | Removes hardness |
|---|---|---|
| Portable softener | Hose fittings, no plumbing changes | Yes, until it needs salt |
| Electronic descaler | Clips around a pipe, needs an outlet | No (makers describe scale reduction) |
| Whole-house softener | Main line, drain and power | Yes |
Portable softeners
Sized in gallons between regenerations: grain rating divided by hardness. Examples: NPGLOBAL NPG-124 16,000-Grain Portable Water Softener, Camco TastePURE 40655 10,000-Grain Portable Water Softener.
Ask first
Any change to the building's plumbing needs the owner's permission and, where required, a licensed plumber.
Products mentioned
Portable / RV softener · NPGLOBAL
NPGLOBAL NPG-124 16,000-Grain Portable Water Softener
16,000 grains
Portable / RV softener · Camco
Camco TastePURE 40655 10,000-Grain Portable Water Softener
4 GPM
Electronic descaler · briskspring
briskspring J-600-BS Electronic Water Descaler
Electronic descaler · 17.6 GPM
Questions readers ask
Can I put a water softener in an apartment?
A whole-house unit usually needs the owner's permission and a drain; portable and clip-on units don't change the plumbing.
Do shower-head softeners work?
Shower filters don't use ion exchange and don't remove hardness the way a softener does.