Can expired hot tub test strips give inaccurate readings?

Yes. Test strips have a limited shelf life, and results can become unreliable after the expiry date. Moisture and poor storage can also affect strips before they expire. Check the date on the container, keep the lid tightly closed and store it indoors in a dry place at room temperature. Take strips out with dry fingers and avoid touching the test pads.

Use the instructions and colour chart supplied with that exact bottle, including the dipping and reading times. Different strips do not necessarily use the same procedure. If a result seems unlikely, repeat the test with fresh strips suitable for your sanitizer system before making a large chemical adjustment. Legacy Spas can provide a showroom water test to help investigate conflicting results; bring the strip container and a note of any products you have recently added.