Best Water Softener for Phoenix, AZ — 17 Things to Know BEFORE You Buy!

Written by Craig "The Water Guy" Phillips

1. The Local Water Problem in Phoenix, AZ

If you live in Phoenix and your 5-year-old tankless water heater just died, you're not alone. Phoenix homeowners replace water heaters 40% more frequently than the national average, and the culprit isn't Arizona's brutal summer heat—it's what's flowing through your pipes every single day.

Phoenix's water measures 12.3 grains per gallon (GPG), officially classified as "very hard" water. To put this in perspective, imagine your water as liquid sandpaper flowing through every fixture, appliance, and pipe in your home. Each grain per gallon represents 17.1 milligrams of dissolved calcium and magnesium minerals per liter—minerals that were perfectly fine when they were part of the Colorado River basin's limestone formations, but become destructive the moment they enter your home's plumbing system.

Phoenix draws its water primarily from the Colorado River via the Central Arizona Project canal, plus groundwater from the Salt River Valley aquifer system. Both sources pick up massive mineral loads as they flow through and sit in contact with calcium-rich geological formations. The result is water so mineral-dense that it leaves visible white scale on every surface it touches.

At 12.3 GPG, Phoenix water falls into the "very hard" classification—a level where mineral deposits form rapidly and damage becomes measurable within months, not years. For the average Phoenix household, this translates to approximately $1,200 in additional annual costs from reduced appliance efficiency, increased soap and detergent usage, higher energy bills, and accelerated replacement schedules for everything from coffee makers to washing machines.

2. What 12.3 GPG Does to Your Home

At 12.3 GPG, calcium carbonate begins coating your water heater elements within weeks of installation. The Phoenix hardness level causes approximately 12-15% efficiency loss in the first year alone. For a standard 40-gallon electric water heater, this means your unit will consume an extra 400-500 kWh annually just to maintain the same hot water output—adding roughly $50-65 to your yearly electric bill even before accounting for the shortened lifespan.

The scale formation process accelerates dramatically at Phoenix's hardness level. When water containing 12.3 GPG of dissolved minerals gets heated above 140°F, calcium and magnesium ions precipitate out and bond directly to metal surfaces. Inside your water heater tank, this creates an insulating layer that forces the heating elements to work progressively harder. A tankless unit—which heats water on-demand to 180°F or higher—sees scale buildup so rapid that many manufacturers void warranties in Phoenix unless a water softener is installed upstream.

Your home's pipes face a similar assault from Phoenix's mineral-dense water. In copper pipes, 12.3 GPG water creates a gradual calcite buildup that reduces internal diameter over time. Galvanized steel pipes—still found in many Phoenix homes built before 1980—are particularly vulnerable. The calcium deposits create rough interior surfaces that catch more minerals, accelerating the narrowing process. A 3/4-inch supply line can lose 20-30% of its flow capacity within 8-10 years at Phoenix's hardness level.

Appliance lifespans in Phoenix homes tell the story clearly. Dishwashers typically last 6-7 years instead of the national average of 10 years. Washing machines see similar reductions. The mineral buildup clogs spray arms, coats sensors, and creates scaling inside pumps and valves. Coffee makers and ice machines fail even faster—often within 2-3 years—as their smaller internal passages become completely blocked by calcite deposits.

The soap and detergent waste at 12.3 GPG becomes a significant household expense. Calcium and magnesium ions react chemically with soap molecules, forming insoluble precipitates instead of cleansing lather. Phoenix households typically use 3-4 times more laundry detergent, dish soap, and body wash compared to homes with soft water. For a family of four, this represents approximately $180-220 in additional cleaning product costs annually.

Phoenix residents frequently report dry, itchy skin and dull, brittle hair—direct results of 12.3 GPG mineral exposure. The calcium ions strip natural oils from skin and form microscopic deposits on hair shafts. Children with eczema or sensitive skin often see symptoms worsen measurably after moving to Phoenix from softer-water cities.

Laundry emerges from Phoenix washing machines noticeably different. Fabrics feel stiff and scratchy as mineral deposits embed in fibers. White clothes develop a grayish tinge from accumulated calcium carbonate. Towels lose their absorbency. Dark colors fade faster as minerals create microscopic abrasions during wash cycles.

The cumulative "hard water tax" for a Phoenix household at 12.3 GPG totals approximately $1,200-1,400 annually when combining increased energy costs, excess soap usage, accelerated appliance depreciation, and additional maintenance requirements.

3. Phoenix's Specific Contaminant Profile

Beyond the challenging 12.3 GPG hardness baseline, Phoenix residents are also contending with chloramine, fluoride, and sediment—each of which interacts with water hardness in its own problematic way.

Chloramine in Phoenix Water

Phoenix water treatment facilities use chloramine as their primary disinfectant instead of traditional chlorine. Chloramine is created by combining chlorine with ammonia, producing a more stable disinfectant that doesn't dissipate as quickly during the long journey from treatment plants to your tap through Phoenix's extensive distribution network.

At 12.3 GPG hardness, chloramine becomes more problematic than it would be in soft water cities. The mineral deposits from hard water create rough surfaces inside pipes and fixtures where chloramine can concentrate and react. This leads to stronger chemical odors and taste issues. Many Phoenix residents describe their tap water as having a "medicinal" or "band-aid" smell, particularly noticeable when running hot water.

Chloramine poses specific challenges because it's much harder to remove than standard chlorine. Standard activated carbon filters—the type found in most pitcher filters and basic whole-house systems—cannot effectively remove chloramine. Only catalytic carbon media can break the chlorine-ammonia bond. This means Phoenix residents need specialized filtration if they want to address the chloramine while also solving the 12.3 GPG hardness problem.

The EPA allows up to 4.0 mg/L of chloramine in drinking water, and Phoenix typically maintains levels between 1.5-2.5 mg/L. While this is well within federal guidelines, chloramine can be toxic to fish (aquarium owners must dechlorinate Phoenix water) and problematic for dialysis patients. The SoftPro Elite HE softener alone does not remove chloramine—Phoenix residents concerned about chloramine should consider a catalytic carbon whole-house filter installed upstream of their softener.

Fluoride in Phoenix Water

Phoenix intentionally adds fluoride to the water supply at approximately 0.7 mg/L for dental health benefits. This is the optimal level recommended by the CDC and American Dental Association. The fluoride comes from carefully controlled additions at the treatment plant, not from natural geological sources.

In combination with 12.3 GPG hardness, fluoride can contribute to additional white spotting on glassware and dishes. The calcium carbonate deposits from hard water create rough surfaces where fluoride compounds can adhere more readily. Phoenix residents often notice that their dishwasher glassware shows heavier white filming compared to what they experienced in softer-water cities.

Water softeners do not remove fluoride—this needs to be clearly understood. The ion exchange process that removes calcium and magnesium minerals has no effect on fluoride compounds. The EPA's maximum allowable fluoride level is 4.0 mg/L, and Phoenix maintains levels well below this threshold. Residents who prefer to remove fluoride from their drinking water should consider a reverse osmosis system at their kitchen tap in addition to whole-house water softening.

Sediment in Phoenix Water

Phoenix's water distribution system occasionally delivers visible sediment, particularly in older neighborhoods and during periods of high system demand. The sediment typically consists of pipe scale particles, rust flakes from aging infrastructure, and mineral particles that settle out during the treatment process.

At 12.3 GPG, sediment becomes more problematic because the hard water accelerates pipe corrosion throughout Phoenix's distribution network. Iron oxide particles (rust) and calcium carbonate scale flakes break free from pipe walls more frequently in very hard water systems. These particles can clog aerators, damage washing machine screens, and—most critically for water softener owners—foul the resin bed that removes hardness minerals.

Sediment in water softener resin tanks acts like sandpaper, gradually damaging the ion exchange beads that remove calcium and magnesium. This is why pre-filtration is essential for Phoenix installations. The SoftPro Elite HE includes a built-in sediment pre-filter specifically designed to capture particles before they reach the resin tank, extending system life in challenging water conditions like Phoenix's.

4. Why Most Phoenix Homeowners Pick the Wrong Softener

Walk through any Phoenix neighborhood built in the last decade, and you'll find garages filled with undersized water softeners that never quite solved the problem. Here are the four critical mistakes that lead Phoenix homeowners to waste money on systems that can't handle 12.3 GPG water.

Mistake 1: Buying on Price Alone

A 24,000-grain softener that works adequately in a 5 GPG city like Seattle will be completely overwhelmed by Phoenix's 12.3 GPG demand. The resin exhaustion happens more than twice as fast, meaning regeneration cycles every 2-3 days instead of weekly. This constant regeneration wastes salt and water while still allowing periodic hard water breakthrough during peak usage periods.

Phoenix households need grain capacity sized for 12.3 GPG consumption, not national averages. An undersized unit forces residents to choose between frequent regeneration (wasting salt and water) or occasional hard water breakthrough (defeating the purpose of having a softener).

Mistake 2: Confusing Softeners with Filters

Water softeners use ion exchange resin to remove calcium and magnesium—period. They do not reliably remove chloramine, fluoride, or sediment. Phoenix residents dealing with both 12.3 GPG hardness and concerns about chloramine or sediment need a properly sequenced two-stage approach: appropriate pre-filtration followed by correctly sized water softening.

Many Phoenix homeowners buy combination units or all-in-one systems thinking they're getting better value. In practice, these hybrid systems often compromise on both filtration and softening performance. It's more effective to address Phoenix's layered water challenges with purpose-built equipment for each issue.

Mistake 3: Ignoring Grain Capacity Mathematics

Here's the formula every Phoenix homeowner should understand:

[Number of People] × 75 gallons/day × 12.3 GPG = daily grain demand

For a 4-person Phoenix household: 4 × 75 × 12.3 = 2,460 grains consumed daily

Multiply by 7 days, and you need 17,220 grains of capacity per week. Add a 20% buffer for high-usage days, and the minimum becomes approximately 20,650 grains. This means Phoenix households need at least a 32,000-grain system, with 48,000 grains being more practical for consistent performance.

Mistake 4: Overlooking Salt Efficiency at 12.3 GPG

At Phoenix's hardness level, a softener regenerates 2-3 times more frequently than it would in a moderately hard water city. An inefficient unit that uses 18 pounds of salt per regeneration becomes expensive quickly when regenerating every 5-7 days. Over 10 years, the difference between an efficient system (8-10 pounds per cycle) and an inefficient one compounds to thousands of dollars in additional salt costs for Phoenix residents.

What to Do Next

Before shopping for any water softener in Phoenix, get your exact water hardness tested professionally. While 12.3 GPG is the city average, some neighborhoods test higher, especially areas served by groundwater wells. Call a local water treatment company for a comprehensive test that measures hardness, iron, and pH levels specific to your address. This baseline data ensures you size your system correctly for your actual conditions, not citywide averages.

5. The SoftPro Elite HE: Built for Phoenix's Water

After evaluating Phoenix's water hardness of 12.3 GPG and the presence of chloramine, fluoride, and sediment in the local supply, one system consistently rises to the top for Phoenix homeowners: the SoftPro Elite HE Water Softener.

Salt-Based Ion Exchange for 12.3 GPG Performance

Salt-free systems—despite their marketing claims—do not actually remove hardness minerals from water. They attempt to change calcium and magnesium crystal structure through template-assisted crystallization, but the minerals remain in solution. At 12.3 GPG, this approach fails completely. Phoenix residents need true mineral removal, which only happens through cation exchange resin that physically trades calcium and magnesium ions for sodium ions.

The SoftPro Elite HE uses high-capacity ion exchange resin specifically rated for very hard water applications. Each resin bead can handle multiple calcium and magnesium extractions before regeneration is required. This matters in Phoenix because frequent resin cycling at 12.3 GPG puts stress on the exchange media—lower-quality resins begin breaking down within 18-24 months under Phoenix conditions.

Demand-Initiated Regeneration (DIR) Technology

At 12.3 GPG, resin beds exhaust much faster than they would in moderately hard water cities. Traditional timer-based regeneration systems guess when resin is spent, leading to either hard water breakthrough (under-regeneration) or salt and water waste (over-regeneration). For Phoenix households consuming 2,400+ grains daily, this guessing game becomes operationally critical.

The SoftPro Elite HE monitors actual water usage and calculates real-time grain depletion. Regeneration occurs only when the resin is actually approaching exhaustion. During Phoenix's peak summer months when water usage spikes for pools and landscaping, the system adjusts automatically. During winter months with lower consumption, it avoids unnecessary regeneration cycles.

NSF/ANSI Standard 44 Certified Components

Third-party certification verifies that the resin, control valve, and brine tank meet strict performance and materials safety standards. For Phoenix residents already managing chloramine and fluoride in their water supply, knowing the softening process itself doesn't introduce additional contaminants provides important peace of mind.

NSF Standard 44 also verifies that the system can actually deliver the rated grain capacity under continuous use conditions. Many uncertified softeners fail to meet their advertised capacity when tested independently. In Phoenix's demanding 12.3 GPG environment, this performance verification becomes essential rather than optional.

Multiple Grain Capacity Options (32K, 48K, 64K, 80K)

Phoenix households need right-sized capacity for 12.3 GPG consumption patterns. The SoftPro Elite HE offers four grain capacity tiers, allowing precise matching to household size and usage patterns:

For a typical 4-person Phoenix household consuming 2,460 grains daily: 48,000-grain capacity provides 7-8 days between regenerations with a comfortable buffer for high-usage periods. The 32,000-grain size works for smaller households (1-2 people), while larger families or homes with pools should consider 64,000+ grain capacity.

10-Year Manufacturer Warranty

At 12.3 GPG, softener resin sees heavy daily mineral extraction cycles that would be considered extreme use in softer-water cities. A 10-year warranty provides Phoenix homeowners with protection during the years when hardness-related stress on internal components is highest. This warranty coverage includes the control valve, resin tank, and electronic controls—the components most likely to need service under Phoenix's demanding conditions.

Self-Cleaning Sediment Pre-Filter Integration

Phoenix's distribution system sediment would gradually damage standard softener resin without proper pre-filtration. The SoftPro Elite HE includes an integrated sediment filter that captures particles before they reach the resin tank. During each regeneration cycle, this pre-filter backwashes itself clean, preventing the maintenance headaches that plague other systems in Phoenix's challenging water conditions.

This automatic cleaning capability matters significantly in Phoenix. Manual sediment filters require homeowners to remember replacement schedules and handle dirty filter cartridges. The SoftPro's integrated approach removes this maintenance burden while providing superior resin protection.

For Phoenix households dealing with 12.3 GPG of water hardness and the compounding presence of chloramine, fluoride, and sediment, the SoftPro Elite HE is not a comfort upgrade—it is infrastructure protection for your home.

Homeowner Checklist

Before purchasing any water softener in Phoenix, verify these four requirements: (1) Confirm your home's main water line can accommodate a 1-inch bypass valve—older Phoenix homes sometimes have 3/4-inch supply lines that limit softener selection; (2) Locate your electrical panel and verify a 120V outlet is available within 10 feet of the planned installation site; (3) Identify your floor drain or suitable drain location for regeneration discharge—Phoenix homes built before 1990 sometimes lack convenient drainage; (4) Measure your available floor space—the SoftPro Elite HE requires approximately 18 inches by 36 inches of clearance for service access.

6. How to Size Your Softener for Phoenix

Proper sizing for Phoenix's 12.3 GPG water requires precise calculation, not guessing based on national averages. Follow this step-by-step process to determine the right grain capacity for your specific household.

Step 1: Count household members, including anyone who lives in the home more than 4 days per week.

Step 2: Multiply by 75 gallons per person per day. This accounts for drinking, cooking, bathing, laundry, and dishwashing. Phoenix residents with pools should add 50 gallons daily for backwashing and splash-out replacement.

Step 3: Multiply household gallons × 12.3 GPG = daily grain demand

Step 4: Multiply daily grains × 7 = weekly grain consumption

Step 5: Add 20% buffer for high-usage days and system efficiency

Step 6: Match to SoftPro Elite HE grain tier

Here's the complete calculation for a 4-person Phoenix household:

4 people × 75 gallons = 300 gallons daily

300 gallons × 12.3 GPG = 3,690 grains consumed daily

3,690 grains × 7 days = 25,830 grains per week

25,830 grains × 1.2 (20% buffer) = 31,000 grains needed

Recommendation: 48,000-grain SoftPro Elite HE for optimal 7-8 day regeneration cycles

The 48,000-grain capacity provides comfortable margin above the calculated 31,000-grain requirement, ensuring regeneration every 7-8 days under normal usage. This frequency maximizes salt efficiency while preventing hard water breakthrough during Phoenix's peak summer usage periods.

7. Installation in Phoenix: What to Know

Phoenix does not require licensed plumber installation for residential water softeners, but the city does have specific requirements for drainage and backflow prevention that affect DIY installations. Most Phoenix homeowners can legally install their own softener, though professional installation ensures proper integration with existing plumbing and compliance with local codes.

Proper placement requires installation after your main shutoff valve but before the water heater and any other treatment equipment. In Phoenix homes, this typically means installation in the garage, utility room, or exterior mechanical area. The softener needs protection from direct sunlight and freezing temperatures—even Phoenix can see overnight lows in the 30s during December and January.

Regeneration discharge requires a suitable drain line connection. Phoenix homes built after 1985 typically have floor drains in garage utility areas. Older homes may require a drain line run to a laundry sink, outside irrigation drain, or main sewer cleanout. The discharge line cannot connect directly to the sewer system without proper air gap separation per Phoenix municipal code.

Phoenix municipal water pressure typically ranges from 45-65 PSI, which works well with the SoftPro Elite HE's operating requirements. Homes in elevated areas of Phoenix (Ahwatukee, North Phoenix foothills) sometimes experience lower pressure that may require a booster pump. Test your home's pressure before installation to ensure adequate flow rates through the softener system.

For Phoenix's 12.3 GPG hardness level, use only evaporated salt pellets in your brine tank. Solar crystals and rock salt contain impurities that create excessive brine tank residue at high regeneration frequencies. Evaporated pellets cost 20-30% more but provide 99.9% purity, reducing maintenance and extending system life under Phoenix's demanding conditions.

Check salt levels monthly during your first year of operation to establish consumption patterns at 12.3 GPG. Most Phoenix households use 40-60 pounds of salt monthly depending on family size and water usage. Keep salt level 2-3 inches above the water line in the brine tank, but never fill more than 2/3 full to allow proper mixing during regeneration.

8. Maintenance Schedule for Phoenix Homeowners

Phoenix's 12.3 GPG hardness requires more frequent maintenance attention than softeners in moderate hardness cities. The high mineral load creates accelerated wear on all system components, making preventive care essential for long-term performance.

Monthly Tasks:

Check salt level—consumption is high at 12.3 GPG, typically 40-60 pounds monthly for a 4-person household. Inspect for salt bridges, which are hard crusts that form above the water line and prevent proper regeneration. Break up any bridges with a broom handle, being careful not to damage the brine tank walls. Verify the bypass valve remains in service position—it's easy to accidentally bump these valves during routine access.

Every 3 Months:

Clean the brine tank by removing undissolved salt residue and wiping down the interior walls. Test post-softener water hardness with a test strip to confirm output remains under 1 GPG—any reading above 1 GPG indicates potential resin exhaustion or system malfunction. Inspect the pre-filter housing for sediment accumulation, particularly during summer months when Phoenix's distribution system sees higher particulate levels.

Annually:

Perform complete brine tank cleaning by dissolving and removing all salt, scrubbing tank walls, and refilling with fresh evaporated pellets. Conduct a resin bed performance audit by testing water hardness at multiple taps throughout your home. If post-softener hardness creeps above 1 GPG consistently, the resin may need cleaning with specialized resin cleaner or replacement.

Review regeneration cycle timing and salt dosage to ensure optimal efficiency. Phoenix's seasonal water usage variations (higher summer consumption for pools and landscaping) may require control valve adjustments for peak performance.

Every 5 Years:

Evaluate resin replacement based on system performance and water quality testing. At 12.3 GPG, softener resin experiences more mineral extraction cycles annually than resin in moderate hardness cities. While quality resin can last 8-12 years, Phoenix conditions may require replacement at the 5-7 year mark if output quality declines.

Phoenix residents should establish baseline water hardness readings immediately after installation and retest quarterly to track long-term system performance. Home test kits are available at most Phoenix hardware stores, or contact a local water treatment company for professional testing.

9. Frequently Asked Questions for Phoenix Residents

9. Is Phoenix's water at 12.3 GPG dangerous to drink?

Phoenix's 12.3 GPG hardness is not a health hazard—calcium and magnesium are actually beneficial minerals that contribute to daily nutritional needs. The EPA has no maximum hardness limit for drinking water safety. The problems with 12.3 GPG are entirely related to plumbing, appliance damage, and quality of life issues like dry skin and poor soap performance, not health risks.

10. Will a water softener remove chloramine from Phoenix water?

No, the SoftPro Elite HE softener does not remove chloramine. Ion exchange resin removes calcium and magnesium minerals but has no effect on chloramine disinfectant. Phoenix residents concerned about chloramine taste and odor should install a catalytic carbon whole-house filter upstream of their softener. Standard activated carbon filters cannot remove chloramine effectively.

11. How much salt will I use per month in Phoenix at 12.3 GPG?

A typical 4-person Phoenix household consumes 40-60 pounds of salt monthly at 12.3 GPG hardness. This is 2-3 times higher than salt consumption in moderately hard water cities because regeneration occurs more frequently. During summer months with higher water usage, consumption can reach 70+ pounds monthly. Budget approximately $15-25 monthly for evaporated salt pellets.

12. Does Phoenix require a permit to install a water softener?

Phoenix does not require permits for residential water softener installation. However, the discharge drain connection must comply with local plumbing codes, including proper air gap separation from direct sewer connections. If you're adding new electrical outlets or modifying main supply lines, those alterations may require permits. Check with Phoenix's Development Services Department for complex installations.

13. Why does soft water feel slippery in the shower?

Soft water allows soap and shampoo to create true lather instead of forming scum with calcium ions. Phoenix residents accustomed to 12.3 GPG water often interpret this normal soap performance as "slippery" because they're used to calcium ions preventing proper cleansing action. This sensation is actually an indication that soap is working correctly and your skin is becoming properly clean.

14. How quickly will I see results after installing a softener in Phoenix?

At 12.3 GPG, you'll notice immediate differences in soap lathering and reduced water spotting within 24 hours of installation. Existing scale deposits in your water heater and pipes will take 3-6 months to gradually dissolve in the soft water. Appliance performance improvements become evident over several months as mineral buildup slowly clears from internal components.

15. Can the SoftPro Elite HE handle Phoenix's water without a separate filter?

The SoftPro Elite HE effectively handles 12.3 GPG hardness and includes sediment pre-filtration, but it does not address chloramine or fluoride removal. Phoenix residents satisfied with chloramine taste and odor can use the softener alone. Those wanting chloramine removal should add catalytic carbon filtration. For fluoride removal from drinking water, consider a reverse osmosis system at the kitchen tap.

16. Final Verdict for Phoenix

Phoenix's aggressive 12.3 GPG water hardness demands commercial-grade treatment, not residential compromise solutions. The combination of very hard water, chloramine disinfection, and sediment from aging distribution infrastructure creates a layered challenge that requires purposeful equipment selection.

Chloramine and sediment compound the 12.3 GPG hardness problem by creating additional chemical reactions and physical wear on plumbing components. Standard water softeners struggle under these conditions, but the SoftPro Elite HE is specifically designed for challenging water like Phoenix provides. The demand-initiated regeneration prevents hard water breakthrough during peak summer usage, the certified resin handles continuous mineral extraction without premature failure, and the integrated sediment pre-filtration protects the system from Phoenix's distribution particulates.

For Phoenix homeowners tired of replacing water heaters every 5-6 years, buying soap by the case, and dealing with chronically dry skin, the SoftPro Elite HE represents infrastructure protection rather than luxury upgrade. The system pays for itself through reduced energy costs, extended appliance lifespans, and dramatically lower soap and detergent consumption.

Check current SoftPro Elite HE pricing and available grain capacities for your Phoenix household size and usage patterns. Focus on the 48,000-grain or 64,000-grain models for optimal performance at 12.3 GPG hardness levels.

Just like the desert blooms with the right water conditions, your Phoenix home's plumbing and appliances will thrive once you remove the mineral assault that flows from every tap in the Valley of the Sun.

17. 30-Day Action Plan

Week 1: Get professional water testing to confirm your specific hardness level and identify any additional contaminants beyond the city average. Request testing for hardness, iron, pH, and chloramine levels.

Week 2: Calculate your household's grain capacity needs using the formula from Section 6. Identify installation requirements including electrical access, drain connections, and available floor space.

Week 3: Research current SoftPro Elite HE pricing from authorized dealers. Compare grain capacity options and verify warranty terms for your specific application.

Week 4: Schedule installation with a certified technician or prepare for DIY installation. Order appropriate salt type (evaporated pellets only for Phoenix) and establish baseline water hardness readings for future comparison.