Total Chlorine Test Results Guide

What this test measures

Total chlorine is all the chlorine in your water — the free chlorine still working as sanitiser, plus the combined chlorine that’s already been used up. A big gap between total and free chlorine is what causes that heavy “swimming pool” smell.

The UK standard

There’s no fixed UK limit for chlorine in drinking water — suppliers add a small, safe residual to keep water clean on its way to you, typically leaving around 0.5 mg/l or less at the tap. In pools, compare total against free chlorine: a difference above roughly 0.5 mg/l means it’s time to refresh the water or shock dose.

Reading your strip

Dip a strip into your sample for two seconds, hold it level and wait 30 seconds. Match the total chlorine pad against the colour chart on your instructions card and read off the closest band. Strips give you a clear range rather than a lab-precise number — exactly what you need for spotting problems and tracking changes over time.

What to do next

• Confirm it first. One strip is a snapshot — re-test with a fresh strip and a fresh sample before acting on a result.
• Strong chlorine taste at home? Fill a jug and stand it in the fridge — the taste fades naturally — or fit a simple carbon filter.
• Pool or hot tub smelling “chloriney”? That’s usually combined chlorine, not too much sanitiser — test free chlorine alongside to see the split.
• Thinking about a filter? Test before and after fitting it so you can see exactly what it changed.