Most pool shops offer free in-store water testing, and it's a genuinely useful service -- it's also, honestly, part of how they sell chemicals. Both things are true at once. Here's what the test actually checks, and how to get the useful part without walking out with more than you need.
What the free test actually checks
The common model (Bunnings' in-store service is a public example of how these work): you bring in a water sample, staff run it through test strips, and enter the results into a kiosk along with your pool's volume, surface type and current condition -- cloudy, green, clear. The kiosk calculates the specific chemicals and quantities your pool needs and prints that out. It's a real calculation from real inputs, not a guess.
The trade-off worth knowing about
The honest criticism of this model: you drive over with a sample, wait for the test, and walk out with a basket of chemicals you're not always sure you actually needed -- because the recommendation is generated by the shop that's also selling you the fix. That doesn't make the test wrong, but it does mean the "buy this much of everything" printout is worth reading with your own numbers in mind, not just accepting as-is.
How to use it without over-buying
- Bring your own recent reading if you have one. If you've tested at home in the last day or two, mention that reading -- it gives you a second data point against the in-store result rather than relying on one test alone.
- Ask for the actual numbers, not just the shopping list. A good pool shop will tell you the ppm readings for chlorine, pH, and alkalinity, not just hand you a basket. If they won't give you the numbers, that's worth noting.
- Buy for the problem you actually have, not a stockpile. If the issue is a one-off chlorine demand spike, you need a shock treatment, not three months of tablets bought "while you're here."
- Use it for the harder tests, and a home kit for the routine ones. In-store testing is worth it for the numbers that are harder to read accurately at home (phosphates, stabiliser/CYA); routine chlorine and pH checks are cheap and easy enough to do yourself 2-3 times a week (see our cleaning-frequency guide) rather than driving to the shop every time.
Chlorine: liquid, granular/tablets, or salt
Whichever way the test result points you, the chlorine you actually buy comes in a few real forms with different trade-offs:
- Liquid chlorine: economical per dose with no filler, but has a short shelf life -- weeks, not months -- so buy only what you'll use soon. Heavy to carry and needs precise measuring.
- Tablets (trichlor): the most convenient -- they sit in a dispenser and dissolve on their own -- with a much longer shelf life that makes bulk buying practical. The trade-off: stabiliser (CYA) accumulates over time from tablets specifically, so it's worth testing for stabiliser buildup periodically rather than only chlorine and pH.
- Salt chlorinators: higher upfront cost to install, but the most automated day to day. See our salt vs chlorine guide for the full cost and maintenance comparison, including the real salt-cell cleaning cadence.
Browse pool shops and chemical suppliers by suburb if you need chemicals, test kits or equipment for a pool you already own -- a different, retail side of pool care from the cleaning and repair services listed elsewhere on this site.