Water Test Assistant
Clearer water.
One check at a time.
Your water-care companion for hot tubs, swim spas and pools. Work out your water volume, follow a strip test and keep your readings together.
Free tools · No account neededYour pool or spa
Save a profile on this device. Check your model year and actual fill level against your manual.
How much water?
Use internal water dimensions in metres, not outside dimensions. Seats, steps and rounded walls reduce actual volume; use your manual or a water meter for spas.
Photos are for visual comparison only. This tool does not measure pad colours or certify that water is safe.
Make the test count
- Use an in-date, dry, correctly stored strip and follow its current bottle instructions.
- Dip as directed, then hold horizontally. The supplied 6-in-1 chart specifies a 30-second development time.
- Read promptly at the specified time. Use even light, avoiding glare, shadows and coloured lighting.
Include your physical comparison chart in the same light. Photos stay in this browser session and are not uploaded or saved to history.
Match your bottle chart
Select the nearest printed value for each pad. Leave uncertain pads as “Not read”. These are your manually entered results, not camera measurements. The current strip does not have a dedicated bromine scale.
Understand before you adjust
Product-label dose calculator
Scale an amount already stated on your exact product label to your confirmed water volume.
Care that keeps you coming back
Find water-care supplies, replacement filters and support from the 365 Hot Tubs team.
Before adding chemicals
Follow the exact product label, including application, circulation, retest and re-entry instructions. Never mix chemicals. Confirm unexpected readings with a suitable independent test before treatment.
No test result here is a “safe to bathe” certificate. This tool is for domestic water-care assistance, not commercial operating records.
Your water diary
Profiles and up to 50 tests are stored only in this browser on this device. Clearing browser data removes them. Shared devices can expose this history.
A clearer approach to water care
Can the camera read my strip automatically?
Not in this release. Lighting, camera processing, strip age and timing affect colour. Automatic readings require strip-specific calibration, controlled physical references and comparison against independent measurements. Your photo is only displayed for manual comparison.
Why are hardness and nitrite not given treatment targets?
The supplied packaging labels these as “hardness” and “nitrite”. We need the supplier to confirm the pad chemistry and pool/spa suitability. We do not assume hardness means calcium hardness, or turn nitrite into nitrate. Bromine also needs an appropriate test.
How is the volume calculated?
Rectangular volume = length × width × average depth × 1,000 litres. Round volume = π × diameter² ÷ 4 × average depth × 1,000. Oval volume = π × length × width ÷ 4 × average depth × 1,000. These are geometric estimates.
Where does the guidance come from?
General references: BISHTA domestic hot tub checks, CDC water testing and chemical safety. Always use the instructions for your equipment and chemical products. Reference review: 23 October 2026.
