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Pool Chemicals Buying Guide — What to Buy & How Much It Costs
Everything you actually need for balanced pool water — and nothing you don't. Buying advice, chemical comparisons, and links to free dosing calculators.
On this page: What you need · Test kits · Chlorine types · Shop by calculator · Grocery store alternatives · Annual costs · Maintenance tools · Starter kits · FAQ
What pool chemicals do you actually need?
Most pool owners buy too many chemicals and use them in the wrong order. The truth is that routine pool maintenance requires only five categories of chemicals. Everything else is situational.
| Chemical | What it does | How often | Calculator |
|---|---|---|---|
| Test kit | Measures chlorine, pH, alkalinity | 2–3× per week | — |
| Chlorine | Sanitizes — kills bacteria and algae | Weekly | Chlorine calculator |
| pH adjuster | Raises or lowers pH to 7.4–7.6 | As needed | pH calculator |
| Alkalinity increaser | Stabilizes pH so it stops bouncing | As needed | Alkalinity calculator |
| Shock | Kills algae, clears cloudy water | Monthly or as needed | Shock calculator |
| Stabilizer (CYA) | Protects chlorine from UV sunlight | Once per season | Stabilizer calculator |
Outdoor pools also need cyanuric acid (stabilizer) once at the start of the season. Salt water pools need pool salt and the same pH/alkalinity chemicals as traditional pools. Not sure how much of each? Use our all-in-one pool chemical calculator — enter your test readings and get exact doses for everything at once.
Step 1 — Get the right test kit
You cannot dose chemicals accurately without testing first. This is where most pool problems start — either guessing, or using test strips that give imprecise readings. Here's which kit to use for what:
🧪 Test strips — weekly routine
Use for: Quick weekly checks when water looks fine
Reads: Chlorine, pH, alkalinity, hardness, CYA (7-in-1)
Accuracy: ±10–20% — good enough for maintenance, not diagnosis
Cost: $15–25 for 50–100 strips
🔬 Liquid reagent kit — accurate readings
Use for: Troubleshooting, SLAM process, CYA testing
Reads: Chlorine (FAS-DPD), pH, alkalinity, hardness, CYA
Accuracy: ±0.2 ppm for chlorine — required for SLAM
Cost: $25–60, lasts 1–2 seasons
📱 FAS-DPD kit — SLAM & high FC
Use for: SLAM process (standard DPD bleaches out above 5 ppm)
Reads: Free chlorine accurately up to 50+ ppm, combined chlorine
Required: You cannot complete a SLAM without this
Cost: $45–65 (Taylor K-2006 is the standard)
📲 Digital tester — salt & pH
Use for: Saltwater pools, precise pH, professional use
Reads: pH and salt levels with digital display
Advantage: No colour-matching, more consistent readings
Cost: $50–150
💡 Recommendation: Test strips for weekly maintenance. Add a liquid reagent kit if you're troubleshooting persistent problems or doing a SLAM. The FAS-DPD kit is specifically required for SLAM — standard strips and DPD kits are useless above 5 ppm FC.
Which type of chlorine should you buy?
This is the single most consequential buying decision for pool chemistry. The wrong chlorine type costs you significantly more money or creates compounding problems over the season.
| Type | Concentration | Adds CYA? | Adds Calcium? | Best for |
|---|---|---|---|---|
| Liquid chlorine sodium hypochlorite |
10–12.5% | No | No | Regular dosing, SLAM, most economical long-term |
| Trichlor tablets 3-inch pucks |
90% | Yes — 6% | No | Convenient maintenance; monitor CYA monthly |
| Cal-hypo granular calcium hypochlorite |
65–78% | No | Yes | Shocking, SLAM, pools with soft water |
| Dichlor granular stabilized granular |
55–62% | Yes — 57% | No | Saltwater pools, spas, pH-neutral dosing |
The key issue with trichlor tablets is CYA accumulation. Each 3-inch tablet adds roughly 0.5 oz of cyanuric acid to your pool. After a full season of tablet use, CYA can climb above 80–100 ppm — at which point your minimum safe chlorine level rises dramatically and the pool becomes prone to algae despite appearing to have chlorine. Test CYA monthly if you use tablets.
Use the CYA/FC calculator to find your correct chlorine minimum based on current CYA level. Use the chlorine calculator for exact dosing amounts.
💧 Liquid chlorine
Most economical at scale. No side effects on CYA or calcium. Best choice for SLAM. Short shelf life — buy fresh.
💊 Trichlor tablets
Slow-dissolving, convenient for floaters. Adds CYA — monitor monthly. Never put tablets directly in skimmer.
⚗️ Cal-hypo granular
High concentration, long shelf life. Pre-dissolve before adding. Raises calcium — monitor if you have hard water.
⚡ Pool shock
High-dose cal-hypo for clearing algae and cloudy water. Use the shock calculator for exact amounts — never guess.
Pool chemicals you can buy cheaper at the grocery store
Several "pool chemicals" are identical to common household products sold at a fraction of the price. Knowing which ones are substitutable saves a significant amount per year.
| Pool product | Grocery/hardware substitute | Savings | What to check |
|---|---|---|---|
| Alkalinity increaser | Baking soda (sodium bicarbonate) | 3–5× cheaper per lb | Must be 100% sodium bicarbonate, no additives |
| Liquid chlorine | Unscented household bleach | Comparable per ppm | 6–8.25% sodium hypochlorite, no fragrances or thickeners |
| Muriatic acid | Hardware store muriatic acid | Same price or cheaper | 31–33% HCl, no rust inhibitors or additives |
| pH Up (soda ash) | Washing soda (sodium carbonate) | 2–3× cheaper per lb | Must be sodium carbonate, not sodium bicarbonate |
What you cannot substitute: Cyanuric acid (stabilizer), cal-hypo shock, calcium chloride, pool salt, and trichlor tablets have no close household equivalents. Buy these as pool-specific products.
⚠️ Never use iodized table salt in a saltwater pool. Never use scented bleach or bleach with thickeners. Never use products with rust inhibitors in the acid. When in doubt, use the pool-grade product.
How much do pool chemicals cost per year?
Annual chemical costs vary significantly based on pool size, chlorine type, and usage. Here are realistic estimates for a 20,000 gallon outdoor pool with moderate use.
| Pool type | Annual chemical cost | Biggest cost driver |
|---|---|---|
| Traditional — liquid chlorine | $250–400/year | Liquid chlorine ($8–15/week in summer) |
| Traditional — tablet chlorine | $350–550/year | Tablets ($30–50/month) + pH/alkalinity from acid effect |
| Saltwater pool | $150–250/year | Salt top-up ($30–60/season) + pH adjusters |
| Hot tub / spa | $100–200/year | Dichlor or bromine + shock |
These estimates exclude equipment (filters, pumps, salt cells) and one-off treatments (SLAM, seasonal opening/closing). Test kits add $25–65 once per season — the Taylor K-2006 FAS-DPD kit is the most accurate option and lasts 1–2 seasons. Use our Chemical Cost Calculator for an estimate tailored to your exact pool size and usage.
Pool supplies FAQs
What pool chemicals do I need for basic maintenance?
The five essentials: a test kit (weekly), chlorine (liquid, tablets, or granular), pH Up and pH Down (soda ash and muriatic acid), alkalinity increaser (baking soda), and shock for monthly or emergency treatment. For outdoor pools, add cyanuric acid (stabilizer) once at the start of the season. Use the pool chemical calculator to get exact doses for everything based on your current test readings.
What's the difference between pool chlorine types?
Liquid chlorine — cheapest long-term, fast-acting, no CYA or calcium side effects, short shelf life. Trichlor tablets — convenient, slow-release, but add CYA with every dose (monitor monthly). Cal-hypo granular — concentrated shock-grade, no CYA but adds calcium. Dichlor — pH-neutral and fast-dissolving, best for spas, but adds CYA like tablets. See the chlorine comparison table above for a full breakdown.
Should I use test strips or a liquid test kit?
Test strips for routine weekly checks — quick and adequate for maintenance. A liquid reagent kit (Taylor K-2006) for diagnosing problems, testing CYA accurately, or doing a SLAM. If your pool keeps having issues despite normal-looking strip readings, switch to a liquid kit — strips can misread chlorine and CYA by enough to cause you to underdose. For SLAM specifically, the FAS-DPD test kit is required — standard kits read zero above 5 ppm FC.
Can I use baking soda and bleach instead of pool chemicals?
Yes for both. Baking soda is identical to alkalinity increaser and 3–5× cheaper per pound. Unscented household bleach (6–8.25% sodium hypochlorite, no additives) works exactly like liquid pool chlorine — just scale the dose for concentration using the chlorine calculator. Muriatic acid from hardware stores is the same product. See the substitution table above for the full list.
How much do pool chemicals cost per year?
A typical 20,000 gallon chlorine pool costs $250–550 per year depending on chlorine type — liquid chlorine is the cheapest option at $250–400. Saltwater pools run $150–250 in ongoing chemicals after the initial salt system investment. Use our Chemical Cost Calculator for an estimate based on your specific pool size, season length, and usage level.
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