Filters and softeners both treat your water, but with different objectives. Understanding those objectives is key to making sense of these systems and whether your household would benefit from them.


Knowing your options

Water filters

A water filter removes many unwanted contaminants from your water to supply better-tasting, cleaner water. Depending on the type of filter, these particles can include:

  • Metals such as arsenic, lead, copper, iron, cadmium and hexavalent chromium
  • Industrial and pharmaceutical byproducts such as pesticides or hormones
  • Chlorine and chloramine
  • PFOS and PFOA (perfluorooctane sulfonate and perfluorooctanoic acid)
  • Sediments and particulates

A reverse osmosis filtration system, usually located under the sink or on a countertop, is a POU (point-of-use) system to treat water for drinking and cooking purposes. A whole-house filter is a POE (point-of-entry) system installed at the main water line to treat water for the entire home.

Whole-house filters allow a much higher flow rate and are designed to treat water for general use such as cleaning, bathing, and laundry applications. Whole-house systems block only large particles, like sand and iron (10-30 microns in size). Basic ones can improve the taste of your water but don’t filter for smaller contaminants.

The water we consume for drinking and cooking must be filtered more carefully to guarantee contaminant-free drinking water. Enter reverse osmosis. Whereas whole-house systems work to filter large particles from the entire home, POU systems remove a broad range of micro-contaminants from a single tap.

If you’re worried about sediment as well as contaminants in your water, we recommend pairing a basic, less expensive whole-house water filter with a point-of-use water filter for the water you ingest.

Water softeners

Have you noticed water spots on your glasses or utensils, soap scum in your tub and on shower doors, or a filmy residue after you wash your hands? Hard water is likely the culprit. A water softener is a type of water filter that expressly targets hard water — that’s water with high amounts of magnesium and calcium in it.

Most water softeners work by swapping mineral ions for sodium ones. The resulting reduced mineral concentrations prevent things like scaly and damaged skin that are common with hard water. Salt-free water softener alternatives are also available for those who don’t want to add salt or chemicals to their water.

Is it necessary to get both a water filter and a water softener?

If a water filter does what it says and filters all of the water in the house, wouldn’t that include magnesium and calcium, the same stuff that makes up hard water?

The short answer is, sometimes — it depends on the type of filter you buy. If you look into getting a whole-house filter that also works as a water softener, then of course it’s going to remove both hard water and other unwanted compounds. But it’s going to be expensive, and oftentimes overkill (think: filtered toilet water).

It’s quite common for homeowners to install both a water softener and filter system to properly treat their incoming water, and these setups offer more complete filtration coverage. When in doubt, consult the CDC guide on which filters are effective for certain contaminants.


Austin Water

The data says…

Austin gets its drinking water from the Colorado River as it flows into Lake Travis and Lake Austin. This water is then treated at one of three treatment plants before being distributed to residents. Austin Water releases quarterly reports on its website.

Self-proclaimed “Water Nerds” at the company Hydroviv use data from Austin Water Utilities, the EPA, and Hydroviv samples to determine potential susceptibilities. Here are a few of their notable results:



Lead enters tap water through older lead service pipes and lead-containing plumbing. Though Austin’s drinking water is in compliance with federal regulations, the EPA, CDC, and American Academy of Pediatrics acknowledge that there is no safe level of lead for children.



Chromium 6 is a toxic metal not regulated by the EPA. In recent years, Austin’s tap water has averaged 175 parts per trillion, levels 8.75 times higher than the concentration determined to have negligible impact on cancer risk.



While most regions use chlorine as their primary disinfectant, Austin’s drinking and tap water is disinfected with chloramine (a mix of chlorine and ammonia). Chloramine is primarily responsible for what many customers report as the “bad taste” of tap water.


Read all of Hydroviv’s findings here. Another researcher, Environmental Working Group, found higher-than-average levels of bromochloroacetic acid, bromodichloromethane, dibromoacetic acid, dibromochloromethane, haloacetic acids, dichloroacetic acid, trihalomethanes, and trichloroacetic acid. If you’re like most people and haven’t heard of these chemicals, they’re considered potential carcinogens.


What does that mean for me?

To be clear, Austin’s tap water is in compliance with federal health-based drinking water standards. It’s safe to drink. But a passing grade from the government doesn’t necessarily mean the water will be free of contaminants or smell/taste good.

Beyond Austin’s city-wide situation, your individual plumbing may present its own unique issues too. There are countless reasons to want additional water filtration, as well as numerous systems designed to address specific issues. Here are some common examples of water problems and their solutions:

If you have dry skin or limescale build-up (white spots on dishes)…water softener

If your water is cloudy or impure…low-micron water filter

If there’s a rotten egg odor or rust stains…iron filtration system

If there’s a chemical odor (chlorine, chloroform, chloramines)…activated carbon filtration system

If a test shows toxins and organic compounds (nitrites and nitrates)…reverse osmosis filtration system


If you’re experiencing an issue not on this list or want to know more, a quick internet search should clue you into the system you need.


Final notes

Making the decision

Deciding whether water softening or water filtration (or both) is best for you depends largely on what’s in your water and the problems you want to address. If spotty dishes or dry, irritated skin are chief complaints in your household, you’re likely dealing with hard water. A softener can alleviate your frustrations. If your water tastes or smells strange, or if you have concerns about the chemical contamination in your drinking water supply, a filter will be the more effective and customizable choice.

As for point-of-entry versus point-of-use filtration, If your annual water-quality report shows that you have a wide range of contaminants or bacteria in your water, an under-sink reverse osmosis (POU) water filter is your best bet. Whole-house (POE) water filters are best for removing large sediment, such as sand and iron.