What free chlorine should a UK pool hold?

1 to 3 ppm free chlorine for outdoor pools, 1 to 2 ppm for indoor pools, with combined chlorine kept below 0.5 ppm.

What is the difference between stabilised and unstabilised chlorine?

Stabilised chlorine contains cyanuric acid that protects free chlorine from sunlight. Unstabilised products work harder per gram but vanish quickly in direct sun.

Can I mix tablet types in the same skimmer?

Never. Mixing tablet chemistries can react violently. Always use a single product per skimmer.

Do I need a separate stabiliser product?

Only if you use unstabilised chlorine such as calcium hypochlorite. Stabilised tablets and granules add cyanuric acid as they dissolve.

How long must I wait before swimming after a chlorine dose?

Wait until free chlorine drops to 3 ppm for a normal top up, or below 5 ppm for a shock dose, with the pump running.

Pool Sanitisers

Pool sanitiser is the daily workhorse that keeps your free chlorine residual inside the safe band. ClearPool ships every common UK format - slow tablets, fast granules, calcium hypochlorite and 14 percent liquid chlorine - so you can pick the right format for your skimmer, dispenser or dosing pump.