At first glance, the difference is visual: in one, the water sits a few centimetres below the edge; in the other, it reaches right up to the top and spills over. But behind that visual difference lie two completely different hydraulic systems.

Skimmer pool

The most common system

  • Cheaper to install and maintain
  • No balance tank needed
  • Lower water and electricity use
Overflow pool

More stylish, more complex

  • Installation cost 15% to 30% higher
  • Filtration oversized by 40-50%
  • The channel and the balance tank need their own cleaning

How each one works, on the inside

In a skimmer pool, the surface water is drawn in through side inlets (the skimmers) located just below the edge, and from there it goes straight to the filtration system. In an overflow pool, water spills over one or more sides into a perimeter channel, drops into a balance tank (a reservoir that stores between 5% and 10% of the pool's total volume), and from there the pump sends it to the treatment system.

Skimmer pool

Overflow pool

The real advantage of an overflow poolThe water is renewed much more continuously and thoroughly, and doesn't bounce off the walls the way it does in a skimmer pool, the result is a pool that tends to stay visually cleaner between visits, although that doesn't replace regular chemical control.

What this means for day-to-day maintenance

In a skimmer pool, maintenance focuses on the skimmer and pre-filter baskets. In an overflow pool, on top of that you also need to check that the perimeter channel doesn't get clogged with plant debris or dirt, plus periodic cleaning of the balance tank, it isn't much more work, but it is different.