Sizing filtration for a pool that never closes

Resort pools run at a load a home pool never sees. Getting turnover and pump sizing right is what keeps the water clear at full occupancy, and it is the single most common thing we are called in to correct.

Turnover is the time the system needs to move the whole volume of the pool through the filter once. A private pool can sit comfortably at six to eight hours. A hotel pool at peak occupancy cannot: the bather load puts far more into the water per hour, and the system has to keep up. Four hours is a more honest starting point, and some briefs need less.

The pump has to be sized to the pipework, not just to the volume. Undersized pipe with an oversized pump gives you velocity, noise and wasted electricity rather than flow. Oversized pipe with a small pump gives you poor skimming. The two are specified together or not at all.

Then there is the filter itself. Sand is forgiving and cheap to run. Cartridge is finer and needs no backwash, which matters where water is expensive or drainage is awkward. Media choice follows the site, not a preference.

The last piece is serviceability. A plant room that cannot be worked on without draining the pool will not be maintained properly, and a system that is not maintained does not perform regardless of how well it was sized. We lay the plant out so the valves can be reached, because somebody has to stand there every week for the next twenty years.