Whole House Water Softener or Whole House Filter: Which One Do You Need?

A whole house water softener takes calcium and magnesium out of the water. That is the scale on the kettle and the soap that will not lather. A whole house filter is aimed at something else, such as taste, smell, grit or iron. They fix different problems. Your water test says which one you have.

A softener is for hardness. A filter is for the thing you want gone.

Everything below is detail on that one line.

Penn State Extension describes ion exchange. Water passes through resin beads coated in sodium. The beads take the calcium and magnesium and release sodium in their place. The water leaving the tank is soft.

Penn State is direct about the rest. It says people often mistake softening for a cleaning process. It blames the ads for that. Soft water is soft. Nothing else has been taken out of it.

The Minnesota Department of Health splits home treatment into two places.

A point of use unit treats one tap. A pitcher, a fridge filter or an under sink unit all sit in that group. A point of entry unit goes on the line where water enters the house and treats all of it.

A whole house filter is a point of entry unit. What it takes out depends on what is inside it. Read the label, not the category.

Two rules from the same page are worth taping to the wall. No single unit can take out everything. And you should pick a unit certified by NSF, UL or the Water Quality Association for the thing you care about.

You cannot pick between these two machines until you know your water.

If a city supplies your water, you already have a report. The Minnesota Department of Health says public systems test for over 100 contaminants. They have to meet Safe Drinking Water Act standards. Your yearly water report lists what came back, hardness included.

If you have a well, that testing is your job. Nobody sends you a report.

Then read the numbers against the guidelines. The EPA publishes 15 secondary standards. They cover taste, color and smell rather than health. Iron sits at 0.3 milligrams per liter. Manganese sits at 0.05. Total dissolved solids sit at 500. Above that line, the EPA lists hardness, deposits and staining.

Two more rows on that table are worth a look. Sulfate sits at 250 milligrams per liter, with a salty taste as the effect. Odor has its own scale, and the EPA names a rotten egg or musty smell as what you notice above it.

Answer three questions.

What is wrong with the water right now? Scale on the kettle, spots on the glasses and soap that will not lather all point at hardness. Color, smell or grit point at something a filter handles.

Where do you want it fixed? The whole house needs a point of entry unit. If you only care about drinking and cooking water, one tap costs far less to treat.

What does the report say? On city water, the yearly report hands you the numbers. On a well, you pay for a test and get the same numbers.

Then buy against those answers, not against the word on the box.

Well water often brings hardness and iron together. That is a filter job and a softener job in the same house.

Order matters. Penn State says oxidized iron clogs the resin. Filtering first keeps it out. So the filter goes first in the pipe and the softener goes second.

You can buy the two as one system. In our table, the cheapest softener on its own is $947. The combined filter and softener systems run from $1,745.72 to $2,940. That is the price of doing two jobs, not a discount for bundling them.

Before you price any equipment, read what the Minnesota Department of Health tells its own residents. It says most people do not need home treatment to protect their health. It says to first try to remove the source of the problem, or to replace the supply with a safer one. Treatment is what you do when neither of those works.

It also warns about water treatment scams, which is a strange thing for a health department to have to put on a page. Take the hint. A test result is your defense against a sales pitch.

Cost sits on a wide scale too. The same department says home treatment runs from less than twenty dollars to thousands of dollars. Treating one tap costs far less than treating the house. In our own table, a softener on its own starts at $947, and the combined filter and softener systems run from $1,745.72 to $2,940.