These three systems often show up in the same quote, sometimes with overlapping promises. They solve different problems, and buying the wrong one is the most common water treatment mistake we see.
The right answer on the Westside also depends heavily on where you live, because hardness ranges from about 6 grains per gallon in LADWP areas to 12 to 16 in Culver City and Inglewood.
What does each system actually do?
A softener removes calcium and magnesium, a salt-free system changes how they behave so they stick less, and carbon removes the disinfectant taste and smell.
| Question | Water softener | Salt-free conditioner | Whole-home carbon | Under-sink RO |
|---|---|---|---|---|
| Removes hardness minerals? | Yes, whole house | No | No | Yes, at one tap |
| Water still tests hard? | No | Yes | Yes | Not at that tap |
| Protects pipes and heaters from scale? | Yes | Yes, by conditioning | No | No |
| Reduces spots on glass? | Yes | No | No | No |
| Removes chlorine and chloramine taste? | No | Only if it has a carbon stage | Yes | Yes, at that tap |
| Needs a drain? | Yes | No | No | Yes, at the sink |
| Needs power? | Yes, for the control valve | No | No | Depends on the unit |
| Uses salt? | Yes | No | No | No |
| Adds sodium? | A small amount | No | No | No, removes it at that tap |
Read across a row to see which system solves a problem, and down a column to see everything one system does.
Why does water from a salt-free system still test hard?
Because the minerals are still in it. A salt-free conditioner changes the form of the calcium so it is less likely to stick to surfaces, but a hardness test measures how much calcium and magnesium is there, and that has not changed.
This is where a lot of disappointment comes from. A salt-free system is scale protection. It helps keep scale from building up inside a water heater and on pipe walls. It does not stop spots on shower glass, because when water evaporates on glass, the minerals are left behind whatever form they are in.
If your goal is spot-free glass and soft-feeling water, only a softener does that. If your goal is protecting the plumbing without salt or a drain, a salt-free system is a reasonable choice, as long as you know the water will still test hard.
When is a softener worth it on the Westside?
When the water is hard enough to cost you money. At 12 to 16 grains in Culver City and Inglewood, it usually is; at about 6 grains in Westchester, Venice and Santa Monica, usually only for homes with a specific scale complaint.
Golden State Water reports Culver City's water at 203 mg/L, about 12 grains, and Inglewood's sources run from 190 to 274 mg/L. At those levels, water heaters fill with sediment and fixtures crust over, and a softener pays for itself in equipment that lasts. See our Culver City and Inglewood pages.
LADWP reports 103 mg/L for Westchester and Venice, and Santa Monica already softens its local groundwater to about the same level. There, most households get more from carbon and RO. See Westchester, Venice and Santa Monica.
When is carbon the right first purchase?
When the complaint is taste or smell. If your water tastes like a pool and scale is not a problem, carbon solves what you actually notice, and a softener would not.
Most Westside utilities use chloramine, which carbon removes when it is sized for enough contact time. Our post on chlorine and chloramine explains why chloramine is harder to remove than chlorine.
How do you tell which problem you actually have?
By the symptom. A pool taste or smell is the disinfectant, white crust and spots are hardness, and brown water after the taps sit is usually the pipes.
Start with what bothers you, not with the equipment. If the complaint is taste or smell, carbon is the fix and hardness is beside the point. If it is crust on faucets, a rumbling water heater or spots on glass, that is hardness, and your utility's figure plus a test at your own tap tells you how much.
If the complaint is discolored water, especially first thing in the morning, look at the pipes before you buy any treatment. Our post on older Westside homes explains how to tell pipe rust from a water supply issue. Many homes have two of these at once, which is why we ask about all three before we recommend anything.
Do you ever need more than one?
Often, in hard-water areas. A softener and carbon solve different problems, so homes in Culver City and Inglewood frequently pair them, with under-sink RO for drinking water.
A common setup in a very hard water home is a sediment pre-filter, a softener, and a catalytic carbon stage on the main line, then RO at the kitchen sink. In a 6-grain home the usual setup is just carbon and RO. The point of testing first is to buy only the pieces that solve your problems.
Not sure which system fits your home? Pipe Dream Plumbing Co. tests your water first and only recommends what solves your actual problem. Call (310) 957-1763.