Whole House Water Filter vs. Water Softener: Do You Need Both?

This is one of the most common questions we get from Columbus homeowners: "Should I get a water softener, a whole house filter, or both?"

The answer depends on what's actually in your water. A water softener and a whole house filter solve fundamentally different problems — and for many Columbus homes, you need both.

A water softener uses ion exchange to remove calcium and magnesium — the minerals that cause hardness. It solves:

• Scale buildup on fixtures, appliances, and pipes
• Poor soap lathering
• Dry skin and hair after showering
• Spots on dishes and glassware
• Reduced appliance efficiency and lifespan

A water softener does not remove chlorine, chloramines, sediment, VOCs, or other chemical contaminants. It only addresses hardness.

A whole house carbon filter (typically using granular activated carbon or catalytic carbon) removes chemical contaminants from all water entering the home. It solves:

• Chlorine taste and odor
• Chloramine removal (important for Columbus city water)
• Volatile organic compounds (VOCs)
• Some pesticides and herbicides
• Hydrogen sulfide (rotten egg smell) in well water
• General taste and odor improvement

A whole house carbon filter does not remove hardness. Your water will still be hard after passing through a carbon filter.

Columbus Division of Water uses chloramines — a combination of chlorine and ammonia — as a disinfectant. Chloramines are more stable than chlorine and persist longer in the distribution system.

The problem: chloramines are harder to remove than chlorine. Standard carbon filters remove chlorine easily but require catalytic carbon to effectively remove chloramines. This is an important distinction when choosing a whole house filter for Columbus city water.

Columbus city water also runs 10–12 gpg hardness — firmly in the "very hard" category. So Columbus homeowners are dealing with both hardness and chloramines.

Central Ohio well water typically has:

• Higher hardness (12–20 gpg in Delaware and Licking counties)
• Iron (ferrous and/or ferric)
• Manganese (in some areas)
• Hydrogen sulfide (rotten egg smell)
• Bacteria (coliform, E. coli) — requires UV treatment
• No chlorine or chloramines (no municipal treatment)

For well water, the typical treatment train is:

1. Sediment pre-filter — removes particles
2. Iron/manganese filter — removes iron and manganese
3. Water softener — removes hardness
4. UV sterilizer — kills bacteria and viruses
5. Carbon filter (optional) — removes hydrogen sulfide and improves taste

For Columbus city water: Yes, most homeowners benefit from both.

• The softener handles hardness (10–12 gpg)
• The catalytic carbon filter handles chloramines and improves taste/odor
• Combined, they address the two main water quality issues in Columbus

For well water: It depends on your test results.

• If you have iron, you need an iron filter (not just a carbon filter)
• If you have hardness above 7 gpg, you need a softener
• If you have bacteria, you need UV treatment
• Carbon filtration may or may not be needed depending on your specific well chemistry

For lightly contaminated city water: A softener alone may be sufficient if you're primarily concerned about hardness and don't mind the chloramine taste.

For Columbus city water, the most effective approach is a combined system:

Stage 1: Sediment pre-filter (5–10 micron) — protects downstream equipment Stage 2: Catalytic carbon filter — removes chloramines, improves taste Stage 3: Water softener — removes hardness

This is exactly how Pure Aqua Columbus configures most city water installations. The carbon filter upstream of the softener also protects the softener resin from chloramine degradation — chloramines can damage resin over time, reducing the softener's effectiveness.

The combined system costs more upfront but addresses both hardness and chemical contamination — the two primary water quality concerns for Columbus homeowners.

For Columbus city water: get both. The combination of catalytic carbon filtration and a properly sized water softener is the complete solution for Central Ohio's water.

For well water: test first, then treat. Well water chemistry varies significantly by location — a water test tells you exactly what you need.

Get a free water test → | See our whole house systems →