Testing pool water is the foundation of all chemistry management. You cannot balance what you do not measure. The right test method depends on your goals: a $20 box of test strips gives quick weekly checks; a $90 Taylor K-2006 reagent kit gives the accuracy you need for real diagnosis; a $40 digital tester combines convenience and accuracy.
Testing pool water is the foundation of all chemistry management. You cannot balance what you do not measure. The right test method depends on your goals: a $20 box of test strips gives quick weekly checks; a $90 Taylor K-2006 reagent kit gives the accuracy you need for real diagnosis; a $40 digital tester combines convenience and accuracy.
This guide is the complete WETYR Pools reference on testing pool water: which test method to choose, what to test (free chlorine, combined chlorine, pH, total alkalinity, calcium hardness, cyanuric acid, salt level if applicable), how to test correctly to get accurate readings, the target ranges, and how often to test.
If you would prefer a service that tests, interprets, and balances on a regular schedule, WETYR Pools provides weekly chemistry service across our maintenance markets. Use the form on this page or email [email protected].
Free chlorine: 1 to 3 ppm. The active sanitizer. Test weekly minimum.
Combined chlorine: 0 to 0.5 ppm. The chloramines, source of the chlorine smell. Shock when over 0.5 ppm.
pH: 7.4 to 7.6. The water acidity. Affects chlorine effectiveness and comfort. Test weekly.
Total alkalinity: 80 to 120 ppm. The buffer that stabilizes pH. Test weekly to monthly.
Calcium hardness: 200 to 400 ppm. Prevents corrosion (too low) and scaling (too high). Test monthly.
Cyanuric acid (stabilizer): 30 to 50 ppm chlorine pools, 60 to 80 ppm salt pools. Protects chlorine from sunlight. Test monthly.
Salt level (salt pools only): 2,700 to 3,400 ppm depending on generator brand. Test monthly.
Total dissolved solids (TDS): less than 2500 ppm above source water. Test annually.
Phosphates: less than 100 ppb. Algae nutrient. Test when chlorine demand is unusually high.
Reagent kits (Taylor K-2006): the gold standard. $80 to $120 for the kit. Tests free chlorine, combined chlorine, pH, total alkalinity, calcium hardness, cyanuric acid. Most accurate. Reagents last 1 to 2 years. Higher learning curve but worth it for serious pool owners.
Test strips: $10 to $20 per pack of 50. Fast (under 1 minute). Less accurate; reads in ranges rather than precise values. Drift wildly at extremes (high chlorine, low alkalinity). Useful for quick weekly checks; not sufficient for diagnosis.
Digital testers (LaMotte ColorQ Pro 7, Pentair eXact iDip): $50 to $300. Combines reagent chemistry with digital readout. Accurate, faster than reagent kits. Reagent refills cost $20 to $50.
Pool store testing: free with chemical purchase. Pool store tests are typically accurate (Taylor reagent based) but variable by store. Useful as a check on home readings.
Photometric testers (commercial): expensive, very accurate. Used by pros for diagnostic visits.
Best practice for serious owners: Taylor K-2006 reagent kit plus a test strip pack for daily quick checks. Casual owners: test strips weekly plus pool store test monthly for accuracy check. Salt pool owners: add a salt-specific test strip or rely on the generator's built-in salt reading.
Take water from elbow depth, away from skimmers and returns. Surface water and water near returns is not representative. For reagent kits, use the provided sample bottle filled to the line.
Reagent: add DPD-1 powder for free chlorine, count drops of FAS-DPD titrant until color changes. Test strip: dip and read against the chart. Note both free chlorine (ideal 1 to 3 ppm) and combined chlorine (ideal under 0.5 ppm). High combined chlorine: shock.
Reagent: add phenol red drops; compare color to chart. Strip: dip and compare. Target 7.4 to 7.6. If under 7.2: raise with sodium carbonate. If over 7.8: lower with muriatic acid. pH drives chlorine effectiveness; adjust whenever out of range.
Reagent: add indicator and count titrant drops until color changes. Strip: dip and compare. Target 80 to 120 ppm. Below 80: raise with sodium bicarbonate. Above 120: lower with acid (this also lowers pH; sequence matters).
Reagent (Taylor K-2006): titration with calcium-specific reagent. Strip: less reliable; pool store test is more accurate for calcium. Target 200 to 400 ppm. Below 200: corrosion risk; raise with calcium chloride. Above 400 in hard-water areas: scaling risk; partial drain dilutes.
Reagent (Taylor or standalone CYA test): add melamine reagent; read turbidity in graduated cylinder. Strip: dip and compare. Target 30 to 50 ppm traditional, 60 to 80 ppm salt. Above 80 ppm 'locks' chlorine effectiveness. Only partial drain lowers CYA.
Keep a log. Date, free chlorine, combined chlorine, pH, total alkalinity, calcium, CYA, salt (if applicable). Over weeks, patterns emerge: which parameters drift, how fast, what causes the drift. Documentation is what separates owners who understand their pool from owners who chase symptoms.
Standard DIY for any pool owner. Test weekly minimum during swim season. Buy a Taylor K-2006 reagent kit if you take pool ownership seriously; strips are fine for casual maintenance.
Call a pro when readings are bouncing wildly week to week (suggests underlying instability), when readings disagree with pool store readings significantly (calibrate your method), or when you want regular chemistry handled on a service schedule.
WETYR Pools provides chemistry testing and balancing as part of weekly service across our maintenance markets. Every visit tests all major parameters with reagent-kit accuracy, adjusts to target, and documents in a service log. Owners receive the log after each visit; the trend over months shows what is stable and what is not.
Cost: weekly service $125 to $225 per month. Standalone chemistry visit: $100 to $200. Diagnostic visit for unusual readings (sodium thiosulfate test, phosphate test, TDS, metals): $150 to $300.
Replace test strips and reagents within their expiration dates; expired reagents drift. Store strips in a cool dry place; do not leave in direct sun. Take samples at elbow depth, away from returns. Read in good light. Use the same method consistently for trending; comparing strip readings to reagent readings shows differences because methods have different accuracy.
Cross-check home readings with pool store readings every 4 to 8 weeks. Significant disagreement points to expired reagents, incorrect technique, or a faulty test kit. Pool store accuracy varies; not every store is reliable.
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20 of the most-asked questions on Reddit, Quora, and pool owner forums, answered by the WETYR Pools team.
Weekly minimum during swim season for chlorine and pH. Monthly for total alkalinity, calcium hardness, cyanuric acid, and salt (if applicable). Annually for TDS. After storms, heavy use, or chemistry events: test immediately.
Taylor K-2006 reagent kit is the gold standard for residential pool owners. Tests free chlorine, combined chlorine, pH, total alkalinity, calcium hardness, cyanuric acid with reagent-kit accuracy. $80 to $120 with reagents lasting 1 to 2 years.
For quick weekly checks: adequate. For diagnosis or precise balancing: not reliable. Strips drift at extremes (high chlorine, low alkalinity) and read in ranges rather than precise values. Use strips plus pool store test as a hybrid; or upgrade to Taylor K-2006.
7.4 to 7.6 is ideal. Below 7.2: corrosion risk and discomfort. Above 7.8: scaling risk and chlorine ineffectiveness.
Free chlorine 1 to 3 ppm. Combined chlorine under 0.5 ppm. Below 1 ppm: insufficient sanitization, algae risk. Above 5 ppm: not safe to swim, fades fabrics.
Free chlorine is the active sanitizer (kills bacteria). Combined chlorine is chloramines (chlorine bound to organic compounds, no longer active sanitizer, source of the strong chlorine smell). Total chlorine equals free plus combined.
Method differences (strips vs reagent), expired reagents, incorrect technique, or pool store inaccuracy. If consistent significant disagreement: cross-check with a fresh reagent kit or different pool store.
1 to 2 years from manufacturing date if stored properly (cool, dry, out of direct sun). Expiration dates are printed on bottles. Expired reagents drift to high readings (alkalinity false-high, chlorine variable).
Yes. Specialty kits or pool store tests for iron, copper, and manganese. Useful diagnostic when staining or chronic chemistry issues suggest metal contamination. Annual or as-needed.
Phosphates are algae nutrients. Test (test strip or pool store) when chlorine demand is unusually high. Treat high phosphates with phosphate remover; reduces algae pressure and chlorine consumption.
Reagent test (Taylor K-2006 or standalone kit): add melamine reagent; read turbidity in graduated cylinder against the dot at the bottom. Strip: dip and compare to chart. Target 30 to 50 ppm traditional, 60 to 80 ppm salt.
All dissolved minerals and chemicals in the water. Useful diagnostic for old water quality. TDS more than 2500 ppm above source water indicates dilution needed (partial drain). Tests with TDS meter or pool store.
Yes. WETYR Pools provides chemistry testing and balancing as part of weekly service or standalone visits across our maintenance markets. Reagent-kit accuracy, documented log. Request through the form on this page or email [email protected].
Salt chlorine generators have built-in salt readers (most accurate). Salt test strips: dip and compare. Digital salt testers: lab accuracy. Target 2,700 to 3,400 ppm depending on generator brand.
Both, with cross-check. Home reading (Taylor K-2006) is accurate when done correctly. Pool store reading is accurate when the store uses fresh reagents and proper technique. Compare every 4 to 8 weeks; investigate large disagreements.
Yes. Quality digital testers (LaMotte ColorQ Pro 7, Pentair eXact iDip) combine reagent chemistry with digital readout. Accurate, faster than manual reagent reading. Reagent refills required.
Pool store: free with chemical purchase. Professional service visit with testing and balancing: $100 to $200. Weekly service including testing: $125 to $225 per month.
DPD (N,N-diethyl-p-phenylenediamine) is the reagent used in chlorine tests. DPD-1 reagent tests free chlorine; FAS-DPD titration tests free and combined chlorine. The Taylor K-2006 uses this method for accuracy.
Possibly: cyanuric acid is extremely high (over 100 ppm) and binding chlorine; combined chlorine is binding free chlorine; or testing technique is off (waited too long between adding reagent and reading). Dilute CYA, break combined chlorine with breakpoint shock.
Yes, but expectations differ. Closed pools should still test chlorine periodically through winter (algae prevention) and pH (winterizing levels). Cold water requires lower chlorine demand. Monthly testing during winter is standard.
Additional authoritative sources on pool water safety, equipment standards, and industry best practices.
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