Water balance and staining repairs in Little Mountain

Every stabilised chlorine tablet adds cyanuric acid, and backwashing does not remove it.

Past a certain level it locks up the chlorine you add, so the pool tests as sanitised and behaves as though it is not. Owners respond by adding more chlorine, which adds more stabiliser.

Rain dilutes the chemistry and washes organic matter off the surrounding block into the pool.

It arrives exactly when the sanitiser has been diluted, which is the combination that turns a pool over within days.

Brown and grey staining is usually metal — iron or manganese — from fill water or from fittings corroding out of sight.

Organic stains lift with chlorine; metal stains set with it. Guessing wrong makes the problem permanent.

A timer set for winter never gets changed back, or a variable-speed pump is left on a speed that suits the power bill rather than the pool.

The chemistry can be correct on paper and still fail if the water is not passing through the filter often enough. It presents as a water-quality problem, not an equipment one.

A chemistry problem that keeps returning usually has a cause on the pad — a tired cell, loaded media, a bypassing valve.

Treating the water repeatedly is the expensive way to manage a fault that should be repaired once.