The Home Duo System Has Two Jobs — And Two Cartridges to Match

The NuvoH2O Home Duo is a 2-in-1 whole-house water treatment system: a salt-free CitraCharge® softener that prevents and removes hard water scale, paired with a carbon taste filter that removes chlorine, VOCs, and contaminants for great-tasting water from every tap.

Because it does two jobs, it has two replaceable components — and both need to be replaced together to maintain full system performance. The NuvoH2O Home Duo Replacement Cartridge & Filter Set (Model 711160) is the genuine, purpose-built replacement set that restores both stages simultaneously, rated for 20,000 gallons or 6 months per set.

What Each Component Does

The CitraCharge® Water Softening Cartridge

The softening cartridge contains NuvoH2O's proprietary CitraCharge® formula — a food-grade citric acid concentrate that chelates hard water minerals (Calcium and Magnesium), binding to them and keeping them dissolved in water so they can't form scale deposits on pipes, fixtures, and appliances.

This chelation process is consumptive: each gallon of hard water treated uses a small amount of CitraCharge®. Over 20,000 gallons, the concentrate depletes. When it's gone, hard water minerals are no longer being chelated — and scale formation resumes throughout your home.

Cartridge dimensions: 2.5" W × 19.9" H | Weight: 2.8 lbs | Max PSI: 125

The Carbon Taste Filter

The carbon filter uses activated carbon to remove chlorine, chloramines, VOCs, and other chemical contaminants from your household water supply. Chlorine is added to municipal water for disinfection — effective for safety, but it creates an unpleasant taste and odor, and it strips natural oils from skin and hair with every shower.

Like the softening cartridge, the carbon filter has a finite capacity. As the activated carbon becomes saturated with adsorbed contaminants, its effectiveness decreases — chlorine taste and odor return, and the filter's ability to remove VOCs diminishes.

Filter dimensions: 2.73" W × 20" H | Weight: 1.7 lbs

Why Replace Both at the Same Time?

The 711160 set replaces both components simultaneously — and this is intentional. Both the softening cartridge and the carbon filter are rated for the same 20,000-gallon / 6-month capacity. Replacing them together:

• Ensures both stages are always performing at full capacity simultaneously
• Eliminates the confusion of tracking two separate replacement schedules
• Simplifies maintenance to a single 6-month task
• Guarantees you're never getting soft water without filtration, or filtration without softening

How Long Does the 711160 Set Last?

The set is rated for 20,000 gallons or 6 months, whichever comes first. Practical guidance by household size:

• 1–2 person household (~50–70 gal/day): 20,000 gallons ≈ 285–400 days — replace at 6 months
• 3–4 person household (~80–100 gal/day): 20,000 gallons ≈ 200–250 days — replace at 6 months
• 5+ person household (~120+ gal/day): 20,000 gallons ≈ 165 days — may need replacement closer to 5 months

For most households: replace every 6 months. Larger families should monitor for the signs below.

Signs Your 711160 Set Needs Replacing

• Scale returning on faucets, showerheads, and glass surfaces
• Chlorine taste or odor returning in tap water — the carbon filter is saturated
• Reduced soap lather — hard water minerals interfering again
• Dry skin or dull hair after showering — chlorine and hard water exposure returning
• White chalky deposits reappearing in the dishwasher or around faucet bases
• 6 months have passed since the last set replacement

Step-by-Step Replacement Guide

1. Turn off the water supply to your Home Duo System.
2. Release pressure by briefly opening a downstream faucet.
3. Remove both old components — the softening cartridge and the carbon filter — from their respective housings.
4. Insert the new CitraCharge® softening cartridge into the softener housing, ensuring it seats fully.
5. Insert the new carbon taste filter into the filter housing, ensuring it seats fully.
6. Secure both housings and restore the water supply.
7. Run water for 2–3 minutes to flush and activate both new components.
8. Check for leaks at both housings and verify proper operation.

Total time: approximately 10–15 minutes. No tools, no plumber required.

What You're Protecting With Every Replacement

Each 711160 set replacement maintains protection across your entire home:

• Water heater: Scale-free operation — prevents the 40% energy efficiency loss caused by scale on heating elements
• Dishwasher: Scale-free spray arms and heating element + chlorine-free wash water for cleaner dishes
• Washing machine: Soft water improves detergent effectiveness and protects drum seals
• Plumbing: Prevents scale narrowing pipes and reducing flow over time
• Skin & hair: Chlorine-free, soft water for every shower
• Drinking water: Chlorine and VOC-free water from every tap

Final Verdict

The NuvoH2O Home Duo Replacement Cartridge & Filter Set (Model 711160) is the only correct replacement for the Home Duo System — restoring both the CitraCharge® softening stage and the carbon filtration stage simultaneously, every 6 months. It's a 10-minute maintenance task that keeps your home's water soft, clean, and great-tasting while protecting thousands of dollars in appliances and plumbing.

Two components. One set. Six months of complete whole-home water protection.

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