Low Maintenance by Design
One of the biggest selling points of fiberglass pools is the reduced maintenance load for the owner. This is largely due to the surface chemistry of the gelcoat.
Surface Advantages
Non-Porous Surface
Concrete is porous; it has microscopic holes where algae can root. Fiberglass gelcoat is smooth and non-porous. Algae slides off, reducing the need for scrubbing and algaecides.
Chemical Stability
Concrete affects water pH (raising it), requiring constant acid addition. Fiberglass is inert. It does not react with the water, leading to stable pH levels and lower chemical costs.
Osmosis Resistance
Modern pools use a Vinylester barrier coat. Older pools made only of polyester sometimes developed «osmotic blisters» (bubbles filled with vinegar-smelling liquid). With proper materials, this is now rare.
Long-Term Care
While durable, the gelcoat can fade (oxidize) over 10-15 years due to UV exposure.
* Prevention: Keep chlorine levels within range (high chlorine attacks gelcoat) and use a pool cover.
* Restoration: Unlike a vinyl liner that must be replaced, a dull fiberglass pool can often be buffed and polished back to a shine, or re-gelcoated in extreme cases.