The routine
Run filtration long enough to turn the pool over at least once a day — around eight hours for a correctly sized pump, longer in a Highveld summer, less in winter. Brush and vacuum as needed, less often than on plaster, and use a soft brush and a mild, pool-safe cleaner only: abrasive pads and harsh cleaners dull gelcoat permanently.
The band that protects gelcoat is pH 7.2–7.4, free chlorine 1–3 ppm and stabiliser (cyanuric acid) 30–50 ppm. The parameter that differs most from a plastered pool is calcium hardness. On marbelite, water low in calcium is actively harmful because it draws calcium out of the cement-based finish. A fibreglass shell has no calcium to protect, so the low end is not the risk — the risk is all at the high end, where excess calcium plus high pH causes scaling, chalking and discolouration that is hard to reverse. International fibreglass manufacturers recommend hardness below about 120 ppm and avoiding calcium-based chlorine products. On total alkalinity the sources disagree, one South African supplier recommending 120–150 ppm for fibreglass where international guidance keeps it at 80–120 ppm, so follow your own manufacturer's written guidance — it governs your warranty.
No South African source publishes running costs specifically for a fibreglass pool, so treat general figures as a guide. At the 2026 working rate of R4.00/kWh, a typical 1.1 kW single-speed pump running six to eight hours a day costs roughly R790–R1,060 a month in electricity, with chemicals and servicing on top. (That is arithmetic: 1.1 kW × 6–8 hours × 30 days × R4.00.) Fibreglass specialists say the smooth surface cuts chemical consumption in summer — a claim nobody has put to numbers, and one of the questions going to our featured builders.
Power and water
Eskom's April 2026 outlook forecast no load-shedding through the April-to-August winter, but localised load reduction and municipal outages still interrupt supply — run filtration on a timer with battery backup, or an outage silently resets the schedule and the pump stays off for days. On water, check your own municipality's current status before you plan a fill; restrictions differ sharply between Cape Town, Johannesburg and eThekwini. Two Cape Town rules apply permanently and are good practice anywhere: a pool must be covered when not in use, and an automatic top-up float valve fed from the municipal supply is not permitted. For a fibreglass owner they matter twice over, because they mean topping up by hand — and a pool left well below skimmer level is drifting towards exactly the unloaded state described next.
The rule that matters most: don't drain it
An empty pool has no water weight resisting the groundwater pressure outside it. In saturated ground — after heavy rain, near the coast, or in clay soils that hold moisture for weeks — that pressure can bulge walls, split a floor or lift the shell out of the ground, and repairs run from R60,000 to well over R200,000. So: never drain a fibreglass pool yourself, and never after heavy rain. If it must be drained — a full reline being the legitimate reason — it is a specialist job, planned for dry ground with pressure relief in place. And because draining is off the table, stains and scale are managed in the water: hold pH, keep calcium and scale under control, and deal with problems early rather than waiting for a reset that isn't coming.
Lifespan, resurfacing and salt
The shell itself is a decades-long asset; the gelcoat surface is what is eventually renewed, and South African sources put that at anywhere from seven to twenty years depending on original manufacturing quality and how the water has been kept. Relining costs roughly R30,000–R75,000 for a family-sized pool at August 2026 prices. Two failure modes are worth knowing by name: fading or chalking, which is chemistry-driven and largely preventable, and osmotic blistering, where water works through the gelcoat and reacts with the resin beneath. Blistering depends far more on how the shell was made than how old it is — a pool can blister in five years or never — and warm water accelerates it, which makes it more relevant on the KwaZulu-Natal coast and in the Lowveld than on the Highveld.
Salt chlorination suits fibreglass well: the surface is inert and unaffected by salt, which is why the two are so often specified together and why fibreglass does well at the coast. What needs attention is everything around the pool — metalwork such as ladders, rails and light surrounds, and soft porous coping such as limestone or travertine. Rinse surrounds with fresh water, seal porous stone and specify good stainless steel.
