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

Written by Craig "The Water Guy" Phillips

1. The Local Water Problem in Scottsdale, AZ

Walk into any Scottsdale appliance repair shop and ask about water heaters. You'll hear the same story repeatedly: tankless units failing within 18 months, traditional tanks losing 35% efficiency by year three, and dishwashers with glass doors so etched they look frosted. The culprit isn't Arizona's heat — it's Scottsdale's punishing 12.8 grains per gallon (GPG) water hardness combined with iron contamination that turns every drop into a mineral cocktail designed to destroy your home's plumbing infrastructure.

Scottsdale's water at 12.8 GPG is classified as very hard. To understand what this means, imagine your water supply as a liquid sandpaper solution. Every gallon contains 12.8 grains of dissolved calcium and magnesium — that's roughly 219 milligrams of rock-forming minerals per liter. These aren't trace amounts. At 12.8 GPG, you're essentially running liquid limestone through copper pipes, across heating elements, and into appliances never designed to handle this mineral load.

The city draws its water supply primarily from the Colorado River via the Central Arizona Project, supplemented by Salt River Project water and groundwater wells. This multi-source approach means Scottsdale residents face seasonal hardness variations, with summer months often pushing GPG levels even higher as groundwater usage increases. The geological journey through Arizona's mineral-rich bedrock saturates every drop with calcium carbonate, magnesium sulfate, and iron oxide.

For Scottsdale homeowners, 12.8 GPG isn't just a water quality statistic — it's a financial time bomb. The typical Scottsdale household loses approximately $2,400 annually to hard water damage: premature appliance replacement, increased energy costs, excessive soap and detergent usage, and plumbing repairs. With median home values exceeding $650,000, protecting your investment from mineral damage isn't optional — it's essential infrastructure maintenance.

2. What 12.8 GPG Does to Your Home

At 12.8 GPG, calcium carbonate doesn't just coat your heating elements — it forms concrete-hard scale deposits that choke water flow and destroy equipment efficiency. Inside your water heater, these minerals crystallize on heating elements at temperatures above 140°F, creating an insulating layer that forces the system to work exponentially harder. A 40-gallon electric water heater in Scottsdale typically loses 8-12% efficiency per year, meaning a unit that costs $85 monthly to operate in year one will consume $110-120 monthly by year three.

The scale formation process accelerates dramatically above 10 GPG. Calcium and magnesium ions precipitate out of solution when heated, bonding to metal surfaces in crystalline structures that grow thicker with each heating cycle. In Scottsdale's desert climate, where water heaters work overtime and mineral concentration increases through evaporation, this process happens faster than in moderate climates. Tankless water heaters are particularly vulnerable — manufacturers like Rinnai and Navien often void warranties on units installed without softeners in areas exceeding 7 GPG.

Your home's copper plumbing faces a dual threat at 12.8 GPG. Scale deposits form most aggressively where water changes temperature or pressure — at joints, valves, and anywhere pipes change direction. In older Scottsdale neighborhoods with galvanized steel pipes, the mineral buildup creates perfect conditions for corrosion acceleration. The scale acts as a trap for iron particles, creating orange-brown deposits that stain fixtures and clog aerators within months of cleaning.

Appliance lifespan reduction at 12.8 GPG follows predictable patterns. Dishwashers typically last 7-8 years instead of the manufacturer-rated 10-12 years. The mineral-rich water etches glass permanently, leaves white film on dishes that no amount of rinse aid can prevent, and clogs spray arms with calcium deposits. Washing machines suffer bearing damage from mineral-stiffened fabrics and require valve replacement 40% more frequently than units in soft-water areas.

Coffee makers, ice machines, and steam appliances fail catastrophically in Scottsdale's hard water environment. At 12.8 GPG, scale buildup blocks internal passages completely within 8-12 months of regular use. High-end espresso machines and built-in coffee systems — common in Scottsdale's luxury homes — require professional descaling every 2-3 months to prevent permanent damage.

The soap and detergent waste at 12.8 GPG creates a hidden monthly expense most Scottsdale residents never calculate. Calcium and magnesium ions react with soap molecules to form insoluble precipitates — the gray scum ring in your bathtub — rather than producing cleansing lather. This chemical reaction means you need 3-4 times more soap, shampoo, dish detergent, and laundry products to achieve the same cleaning power. For a typical Scottsdale household, this translates to $40-60 additional monthly spending on cleaning products.

Skin and hair damage from 12.8 GPG water becomes noticeable within weeks of moving to Scottsdale. Calcium ions strip natural oils from skin, leaving it dry, tight, and prone to irritation. Hair becomes dull and difficult to manage as mineral deposits coat each strand, preventing moisture penetration. Many Scottsdale dermatologists report increased eczema and sensitive skin complaints, particularly among residents relocating from soft-water regions.

The annual "hard water tax" for a Scottsdale household at 12.8 GPG — combining energy waste, premature appliance replacement, excessive product usage, and plumbing repairs — conservatively totals $2,400-3,200 per year. Over a 10-year period, unaddressed hard water costs the average Scottsdale homeowner more than $28,000 in preventable expenses.

3. Scottsdale's Specific Contaminant Profile

Scottsdale's water profile presents a layered challenge: beyond the 12.8 GPG hardness baseline, residents are also contending with iron, chlorine, and sediment — each of which interacts with water hardness in its own way. Understanding these interactions is crucial for Scottsdale homeowners because treating hardness alone won't solve the complete water quality picture.

Iron Contamination in Scottsdale

Iron enters Scottsdale's water supply through two primary pathways: geological leaching from iron-rich desert soil and corrosion of aging distribution pipes. The iron exists primarily as ferrous iron (dissolved and invisible) until it contacts oxygen or chlorine, then oxidizes to ferric iron, creating the familiar red-orange staining on fixtures, pool surfaces, and laundry.

At 12.8 GPG hardness, iron contamination becomes exponentially more problematic. Iron ions bond chemically with calcium deposits, creating compound stains that penetrate deeper into surfaces and resist standard cleaning methods. Scottsdale residents notice this as brown-orange buildup around faucet aerators, permanent staining on white pool plaster, and rust-colored streaks on driveways where sprinkler overspray occurs.

The EPA secondary maximum contaminant level (MCL) for iron is 0.3 mg/L, based on taste and aesthetic concerns rather than health risks. Scottsdale's iron levels typically range from 0.2-0.8 mg/L depending on seasonal groundwater usage and system maintenance. While not immediately dangerous, iron above 0.3 mg/L fouls water softener resin, reducing efficiency and requiring more frequent regeneration cycles.

Standard salt-based water softeners cannot reliably remove iron without pre-filtration. The SoftPro Elite HE requires an upstream iron filter when iron levels exceed 0.3 mg/L — a common situation in Scottsdale. Without proper iron removal, the softener resin develops orange fouling that eventually requires replacement or professional cleaning.

Chlorine Disinfection in Scottsdale

Scottsdale adds chlorine at the water treatment plant as a primary disinfectant, but Arizona's intense heat and long distribution distances require higher chlorine residuals than moderate climates. Summer chlorine levels often reach 3-4 mg/L to maintain effectiveness — well above the taste threshold where most residents notice a "swimming pool" odor and metallic taste.

Chlorine interacts destructively with both hard water minerals and plumbing materials. At 12.8 GPG, chlorine accelerates the formation of disinfection byproducts (THMs and HAAs) as it reacts with mineral-bound organic compounds. These byproducts create the chemical taste many Scottsdale residents associate with tap water, particularly noticeable in coffee, tea, and ice.

The seasonal variation in chlorine levels affects Scottsdale residents predictably. Summer months bring stronger chemical taste and odor as water departments compensate for increased bacterial growth potential in 110°F+ temperatures. Pool owners notice increased chemical demand as higher chlorine residuals in fill water disrupt carefully balanced pool chemistry.

Standard water softeners do not remove chlorine — the ion exchange process targets only hardness minerals. Scottsdale homeowners dealing with both hard water and chlorine taste issues need a two-stage approach: the SoftPro Elite HE for hardness removal paired with an activated carbon whole-house filter for chlorine reduction. The carbon system must be positioned downstream of the softener to prevent chlorine from degrading the softener's rubber seals and control valve components.

Sediment and Turbidity Issues

Sediment in Scottsdale's water comes from two sources: particles suspended during municipal main breaks and repairs, and fine mineral deposits that flake off from scale buildup in distribution pipes. The city's aggressive pipeline replacement program creates temporary turbidity events that affect entire neighborhoods.

At 12.8 GPG hardness, sediment particles act as nucleation sites for accelerated scale formation. Even microscopic particles provide surfaces where calcium and magnesium can precipitate, creating larger, more adherent deposits throughout your home's plumbing system. This is why Scottsdale homes experience faster fixture clogging and more frequent aerator cleaning requirements than areas with similar hardness but lower sediment levels.

Sediment also damages water softener resin through physical abrasion and pore clogging. The SoftPro Elite HE addresses this challenge with an integrated sediment pre-filter that protects the resin bed while extending system service life. This feature is particularly valuable in Scottsdale where both sediment and extreme hardness stress softener components simultaneously.

EPA turbidity standards for finished water require levels below 1 NTU (nephelometric turbidity unit) 95% of the time, with no single measurement exceeding 4 NTU. Scottsdale consistently meets these standards, but temporary spikes during infrastructure work can reach 2-3 NTU, causing visible cloudiness and accelerated filter clogging.

4. Why Most Scottsdale Homeowners Pick the Wrong Softener

Every month, Scottsdale plumbers remove undersized, failed water softeners from homes where well-meaning homeowners bought systems designed for moderate hardness, not Arizona's 12.8 GPG reality. The consequences go beyond wasted money — an inadequate softener provides false confidence while scale damage continues accumulating behind the scenes.

Mistake #1: Buying on Price Alone. A 24,000-grain softener that works perfectly in a 5 GPG city like Seattle will fail a Scottsdale household within days. At 12.8 GPG, a four-person family exhausts 24,000 grains of capacity in under 48 hours, forcing near-constant regeneration cycles that waste salt, water, and electricity while never providing consistently soft water. The math is unforgiving: undersized capacity at extreme hardness levels creates system failure, not savings.

Mistake #2: Confusing Softeners with Filters. Water softeners use ion exchange resin to replace calcium and magnesium ions with sodium ions — they do not remove iron, chlorine, or sediment reliably. Scottsdale residents with 12.8 GPG hardness plus iron and chlorine contamination need coordinated treatment stages, not a single "miracle" unit that promises to solve everything.

Mistake #3: Ignoring Grain Capacity Mathematics. The sizing formula is straightforward but non-negotiable: [People] × 75 gallons/day × 12.8 GPG = daily grain demand. For a four-person Scottsdale household: 4 × 75 × 12.8 = 3,840 grains consumed daily. A 32,000-grain system provides 8.3 days between regenerations — optimal for efficiency and performance. Smaller capacities force excessive regeneration; larger capacities waste salt through over-regeneration.

Mistake #4: Overlooking Salt Efficiency at High GPG Levels. At 12.8 GPG, regeneration frequency matters exponentially for operating costs. An inefficient softener uses 15-18 pounds of salt per regeneration cycle versus 8-10 pounds for a high-efficiency model. Over 10 years in Scottsdale, this difference compounds to 3,000-4,000 additional pounds of salt — representing $800-1,200 in unnecessary expense plus the physical labor of frequent salt loading.

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

After evaluating Scottsdale's water hardness of 12.8 GPG and the presence of iron, chlorine, and sediment in the local supply, one system consistently rises to the top for Scottsdale homeowners: the SoftPro Elite HE Water Softener. This isn't marketing hyperbole — it's the logical engineering solution when you match system capabilities against Arizona's extreme water conditions.

Salt-Based Ion Exchange Technology addresses Scottsdale's core challenge. Salt-free systems do not actually remove hardness minerals — they only attempt to change crystal structure through template-assisted crystallization. At 12.8 GPG, salt-free technology cannot prevent scale formation. The SoftPro Elite HE uses true cation exchange resin to physically replace calcium and magnesium ions with sodium ions — the only proven method that delivers genuinely soft water at this hardness level. Every independent laboratory test confirms this: salt-based systems reduce hardness to under 1 GPG; salt-free systems leave minerals in solution.

Demand-Initiated Regeneration (DIR) becomes operationally essential at 12.8 GPG, not merely convenient. Traditional timer-based systems regenerate on fixed schedules regardless of actual resin exhaustion. At Scottsdale's extreme hardness levels, usage patterns matter enormously — a house party or increased landscape watering can exhaust resin capacity days ahead of schedule. DIR monitors actual grain usage and regenerates only when the resin bed is depleted, preventing hard water breakthrough while eliminating unnecessary salt and water waste.

NSF/ANSI Standard 44 Certified Resin provides crucial assurance for Scottsdale residents already managing multiple water contaminants. This certification verifies the resin meets strict performance benchmarks and materials safety standards — confirming the softening process itself doesn't introduce additional contaminants into your treated water. Given Scottsdale's existing iron and chlorine challenges, knowing your softener meets independent safety standards provides essential peace of mind.

Grain Capacity Options (32K, 48K, 64K, 80K) allow precise matching to Scottsdale household needs at 12.8 GPG. Using our established formula: a four-person household consumes 3,840 grains daily. The 48,000-grain SoftPro Elite HE provides 12.5 days between regenerations — optimal for both efficiency and convenience. The 32,000-grain model regenerates every 8.3 days (acceptable but more frequent), while the 64,000-grain model extends cycles to 16.7 days (efficient but requires more salt per regeneration).

Ten-Year Warranty Coverage protects Scottsdale homeowners during the highest-stress operational period. At 12.8 GPG, softener resin processes more mineral-laden water monthly than systems in moderate climates handle annually. This accelerated wear pattern makes warranty protection essential, not optional. The SoftPro Elite HE's decade-long coverage demonstrates manufacturer confidence in the system's ability to withstand Arizona's demanding conditions.

Compatibility with Iron Pre-Filtration Systems addresses Scottsdale's dual hardness-plus-iron challenge systematically. The SoftPro Elite HE is engineered to operate downstream of iron removal media without flow restrictions or pressure drops that compromise performance. This coordination prevents iron fouling of the softener resin while ensuring both systems operate at peak efficiency. Many softener manufacturers void warranties when iron exceeds 0.3 mg/L — SoftPro supports proper pre-filtration as part of the complete treatment solution.

Self-Cleaning Sediment Pre-Filter Integration protects against Scottsdale's periodic turbidity spikes during municipal maintenance. Before hardness minerals reach the resin tank, suspended particles are captured and automatically backwashed during regeneration cycles. This prevents the particle accumulation that would otherwise clog resin bed pores and reduce ion exchange efficiency. In a city where both sediment events and 12.8 GPG hardness stress system components, this protection extends operational life significantly.

For Scottsdale households dealing with 12.8 GPG of water hardness and the compounding presence of iron, chlorine, and sediment, the SoftPro Elite HE is not a comfort upgrade — it is infrastructure protection for your home. The system's engineering matches the severity of Arizona's water challenges, providing the reliability and performance that lesser units cannot sustain under these conditions.

6. How to Size Your Softener for Scottsdale

Proper sizing at 12.8 GPG eliminates the guesswork that leads most Scottsdale homeowners to choose inadequate systems. The mathematics are straightforward, but the consequences of miscalculation are severe at this hardness level.

Step 1: Count household members accurately. Include full-time residents, frequent guests, and anyone using water regularly. Step 2: Multiply by 75 gallons per person per day — the standard residential consumption rate that accounts for drinking, cooking, bathing, laundry, and dishwashing. Step 3: Multiply household gallons × 12.8 GPG = daily grain demand. This is your non-negotiable minimum capacity requirement.

Step 4: Multiply daily grains by 7 = weekly grain demand. Step 5: Add 20% buffer for high-usage periods — house guests, increased laundry, landscape maintenance, or seasonal variations. Step 6: Match your calculated weekly grain demand to available SoftPro Elite HE capacities: 32,000 / 48,000 / 64,000 / 80,000 grains.

Example calculation for a four-person Scottsdale household at 12.8 GPG: 4 people × 75 gallons × 12.8 GPG = 3,840 grains daily. Weekly demand: 3,840 × 7 = 26,880 grains. With 20% buffer: 26,880 × 1.2 = 32,256 grains weekly. The SoftPro Elite HE 48,000-grain model provides 12.5 days between regenerations — optimal for efficiency while maintaining consistent soft water delivery.

Regeneration frequency impacts both performance and operating costs at 12.8 GPG. Systems regenerating every 5-7 days operate most efficiently, minimizing salt usage while preventing resin exhaustion. More frequent regeneration wastes salt and water; less frequent regeneration risks hard water breakthrough during peak demand periods.

7. Installation in Scottsdale: What to Know

Scottsdale requires licensed plumbing contractors for water softener installations that involve new water line connections, but homeowners can typically replace existing softeners or perform maintenance without permits. Check with Scottsdale's Development Services Department for current requirements, as regulations vary for new construction versus retrofit applications.

Proper placement follows a specific sequence: after the main water shutoff valve and pressure regulator, before the water heater, but after any iron pre-filtration equipment. In Scottsdale's desert climate, avoid outdoor installations where UV exposure and temperature extremes can damage control valves and plastic components. Garage installations work well if shaded from direct sunlight and protected from dust infiltration.

The regeneration drain line requires connection to a floor drain, laundry sink, or sump pit — never directly to septic systems where high salt concentrations can disrupt bacterial processes. Scottsdale's typical municipal water pressure ranges from 45-65 PSI, well within the SoftPro Elite HE's operating range of 20-80 PSI. Higher pressures may require a pressure-reducing valve to prevent premature wear on internal seals.

At 12.8 GPG, use evaporated salt pellets exclusively — highest purity, lowest brine tank residue, and most consistent dissolution. Solar crystals leave more insoluble matter that accumulates over time, reducing brine tank capacity and potentially clogging valves. The extra cost of evaporated pellets pays for itself through reduced maintenance and more reliable operation at extreme hardness levels.

Salt level monitoring becomes more critical at 12.8 GPG due to increased consumption rates. Check brine tank salt levels monthly, maintaining at least 6 inches above the water line. Allow salt to drop too low, and the system cannot generate sufficient brine concentration for complete regeneration — leading to hard water breakthrough and potential resin damage.

8. Maintenance Schedule for Scottsdale Homeowners

At 12.8 GPG, maintenance intervals compress significantly compared to moderate hardness areas — what happens annually elsewhere occurs quarterly in Scottsdale. Establishing a consistent schedule prevents system failures and protects your investment in both the softener and your home's appliances.

Monthly Tasks: Check salt level and consumption rate. At 12.8 GPG, expect 40-60 pounds of salt consumption monthly for a four-person household — significantly higher than the 15-25 pounds typical in moderate climates. Inspect for salt bridges (crusted salt above the brine water line that prevents proper dissolution) and break up any formations with a broom handle. Verify the bypass valve remains in service position and hasn't been accidentally switched.

Quarterly Tasks: Clean the brine tank thoroughly, removing any accumulated salt residue and sediment. Test post-softener water hardness with test strips — readings should consistently show under 1 GPG. If hardness creeps above 1 GPG, investigate iron fouling, inadequate salt levels, or premature resin exhaustion. Clean the sediment pre-filter if your system includes this feature, as Scottsdale's periodic turbidity events can clog filters rapidly.

Annual Tasks: Complete brine tank cleaning with disinfection using unscented bleach solution. Perform comprehensive resin bed performance evaluation — if post-softener hardness consistently exceeds 1 GPG despite adequate salt and proper regeneration timing, resin may need cleaning or replacement. Iron fouling appears as orange discoloration; use iron-specific resin cleaner according to manufacturer specifications.

Conduct annual regeneration cycle audit by manually initiating regeneration and timing each phase. Irregular timing suggests control valve problems that require professional attention. Document salt consumption patterns to identify gradual increases that may indicate resin degradation or system inefficiencies developing over time.

Five-Year Resin Evaluation becomes critical at 12.8 GPG where resin processes extreme mineral loads continuously. Professional resin analysis can determine remaining capacity and predict replacement timing. High-GPG installations typically require resin replacement every 8-12 years versus 15-20 years in moderate climates, making proactive evaluation cost-effective.

Scottsdale-Specific Tip: Order home water test kits annually to monitor any changes in iron or sediment levels that might require system adjustments. Municipal water quality can shift with seasonal source changes, infrastructure updates, or drought conditions affecting groundwater usage ratios.

9. Is Scottsdale's water at 12.8 GPG dangerous to drink?

Scottsdale's 12.8 GPG hardness poses no direct health risks — calcium and magnesium are essential minerals your body needs. The EPA classifies hardness as a secondary (aesthetic) standard, not a primary health standard. However, the minerals that make water "hard" create the scale buildup that damages plumbing, reduces appliance efficiency, and increases household operating costs significantly.

10. Will a water softener remove iron from Scottsdale's water?

Standard water softeners, including the SoftPro Elite HE, are not designed to remove iron reliably. Ion exchange resin can handle trace iron amounts (under 0.3 mg/L), but Scottsdale's iron levels often exceed this threshold. Iron above 0.3 mg/L fouls softener resin, creating orange staining and reducing system efficiency. For Scottsdale homes with elevated iron, install a dedicated iron filter upstream of the softener.

11. How much salt will I use per month in Scottsdale at 12.8 GPG?

A four-person Scottsdale household with a properly sized SoftPro Elite HE will consume approximately 45-65 pounds of salt monthly at 12.8 GPG. This equals 2-3 forty-pound bags per month, costing $15-25 monthly for evaporated salt pellets. Higher consumption indicates system problems, undersizing, or water leaks that need investigation.

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

Scottsdale typically requires permits for new plumbing connections but not for replacing existing softener systems in the same location. Contact Scottsdale Development Services at (480) 312-2500 to confirm current requirements for your specific installation. Licensed contractors handle permit applications as part of their service.

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

Soft water feels slippery because you're experiencing clean skin for the first time without calcium film coating. In Scottsdale's 12.8 GPG water, calcium ions create a "soap scum" layer on skin that many residents mistake for clean rinsing. Soft water allows soap to rinse completely, leaving skin naturally smooth — an adjustment period that typically lasts 1-2 weeks.

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

Immediate improvements include better soap lather, cleaner dishes, and softer skin within 24-48 hours of activation. Scale prevention begins immediately, but existing buildup in appliances and pipes won't dissolve — it simply stops growing. New scale formation ceases, protecting future appliance purchases and plumbing repairs from ongoing damage at 12.8 GPG.

15. Can the SoftPro Elite HE handle Scottsdale's water without separate filters?

The SoftPro Elite HE handles Scottsdale's 12.8 GPG hardness excellently, but iron above 0.3 mg/L requires upstream filtration to prevent resin fouling. Chlorine taste and odor need activated carbon filtration downstream of the softener. Sediment is managed by the integrated pre-filter. Most Scottsdale homes benefit from a coordinated treatment approach rather than relying solely on softening.

16. What maintenance costs should I expect in Scottsdale?

Annual maintenance costs in Scottsdale at 12.8 GPG include $180-300 for salt, $50-75 for replacement pre-filters, and $100-150 for professional service calls if needed. This $330-525 annual investment prevents thousands in appliance damage and energy waste that unaddressed hard water causes in Arizona's extreme conditions.

17. Final Verdict for Scottsdale

Scottsdale's hardness of 12.8 GPG demands professional-grade treatment, not residential compromise solutions. The combination of extreme mineral content plus iron and chlorine contamination creates a water quality challenge that destroys unprotected appliances, wastes energy, and increases household operating costs by thousands annually.

Iron, chlorine, and sediment compound the hardness problem by accelerating scale formation, creating taste issues, and fouling treatment equipment. The SoftPro Elite HE rises to the top for Scottsdale homeowners because its demand-initiated regeneration handles variable mineral loads efficiently, its certified resin withstands high-GPG stress, and its compatibility with pre-filtration addresses the complete contaminant profile systematically.

The system's 48,000-grain capacity matches typical Scottsdale household needs precisely, regenerating every 12-13 days for optimal salt efficiency. Its ten-year warranty provides protection during the high-stress operational period when 12.8 GPG water tests every component continuously. The integrated sediment pre-filtration and iron filter compatibility create a complete solution rather than a partial fix.

For Scottsdale residents, installing the SoftPro Elite HE isn't about water luxury — it's about protecting a significant real estate investment from preventable mineral damage. Check current SoftPro Elite HE pricing and available grain capacities for a Scottsdale household dealing with Arizona's unique water challenges.

In a city where million-dollar homes sit in the shadow of Camelback Mountain and desert sunsets reflect off swimming pools fed by some of America's hardest water, protecting your investment from mineral damage isn't optional — it's as essential as air conditioning.