As more and more people opt to move out of the city to build small family houses in the suburbs and exurbs, the demand for swimming pools continues to grow. And we're not just talking about basic, above-ground vinyl pools. Proper in-ground swimming pools have also become increasingly popular in recent years.

"No one knows the exact numbers, but Czechs have definitely caught up to their Western neighbors when it comes to the percentage of households with their own pool," says Tomáš Eršil, the general manager of GHC Invest.

Eršil should know. His firm, which specializes in water-treatment chemicals and filtration systems, has worked primarily on public swimming pools and large water reservoirs. Over the last few years, however, the company has seen an increase in the number of private pool owners clamoring for its services.

It makes sense that many people who decide to build a family house also choose to install a pool at the same time, says Eršil. "It really reduces some of the supplier costs." Eršil also points out that it's easier to install a pool on a property that is still being landscaped than to tear up an already-existing garden or backyard.

Although many of Eršil's customers continue to come from the ranks of celebrities and well-to-do business managers, a lot of new clients are middle-class Czechs who have saved enough money to have a small piece of luxury in their backyard. "Many of these people used to own a vinyl above-ground pool and now want to upgrade," says Eršil.

The price tag for a large in-ground pool can go as high as 1 million Kč ($39,500). It costs another 20,000 Kč a year to maintain a medium-sized outdoor swimming pool. In spite of this, there are also a growing number of people who want amenities such as whirlpools.

So what are the newest trends in pool products? Eršil says there is a growing demand for more environmentally friendly cleaning systems that use biodegradable substances and don't have a negative impact on the environment. "These products are more expensive than chlorine-based pool cleaners, but quite a lot of people are willing to pay the higher price," says Eršil.

In terms of future trends, Eršil anticipates that people will continue to look for ways to replace chlorine, which is still the main component in the majority of water-treatment systems for public and private pools. And the already demanding Czech customers will become even more spoiled — and that's good news for firms like GHC Invest.