Pool Systems 101
Learn more about saltwater, chlorine, pumps and filters.
Pools are made up of many parts but it's the circulatory systems that keep the water clean and healthy. Here's a primer on what's available.
Saltwater vs. chlorine
Saltwater or saline pools offer a better swimming environment, and while it might feel better on the skin and does not cause eye irritation, it's not without its problems. "A saltwater pool is a great system," says Nick Vitiello, project manager for Lang Pools. "It takes more coddling for the start-up and is initially more expensive than a chlorine pool, but you don't have to handle all the chemicals so it's more user friendly."
Over time, the cost of the salt chemicals is less than traditional chlorine. When you opt for a saltwater or saline pool, your pool's filtering system comes with a chlorine generator. The generator takes in the pool water and makes chlorine that is then sent back out to the pool to sanitize the water. In the end, you are swimming in a lot less chlorine than you would with a traditional chlorine system.
Another advantage besides saving money on buying chlorine or handling the chemicals is that you don't need algaecides because the system naturally helps prevent algae from growing on the walls or in the water. You also don't need to test the water as often but still need to maintain proper pH levels. On the downside, you have to run your pool filter 24/7 to keep generating enough chlorine to clean the pool water.
Salt is corrosive to metal such as pool ladders and handrails that comes in contact with the pool water. Saltwater tends to corrode any metal objects near the pool such as outdoor furniture and even nearby grills. The salt is also corrosive to natural stone, so any paving made of natural materials near the pool that gets splashed will eventually break down unless it's properly sealed to keep out the water. "If you seal the coping every couple of years, it should not be an issue," says Tom Mortland, pool division manager of Liquidscapes. Discuss the pros and cons with your pool professional but know that not every pool company recommends using a salt system. "It damages pools over time," says James Atlas, co-owner of Platinum Pool Care.
Pumps and motors
Whatever pool system you ultimately choose will require a pump to circulate the water through the filter and heater then back to the pool. The newer pumps and motors run more efficiently than the older versions, thus helping to cut down on electric bills.
They now have variable-speed motors that run at a lower rate saving energy that is good for your wallet and the environment. "Pumps used to be about 80 percent efficient but now they are about 93 percent efficient," says Atlas.
There are three kinds of filters for most pools. The most popular is a cartridge filter, which uses fabric cartridges to filter out impurities as the water passes through it. These require minimal maintenance as you simply hose off the cartridges a few times during the swimming season to clean them. They tend to fit into most budgets. "With a cartridge filter, you are not putting chemicals into the sewer system," says Atlas.
A diatomaceous earth filter uses fossilized plankton skeletons to filter the water. These are the most-expensive type of filters and require that you backwash your pool system to clean them. You will end up with what some communities deem hazardous waste, so disposing of spent material could pose a problem depending on where you live. It’s also the most-costly filter to buy.
Finally, the least-expensive filter is the sand-type filter, which uses fine sand to clean the water. This type also requires backwashing to remove impurities but also means that you are wasting water by cleaning the filter.
If you plan to use your pool in the cooler months or at night then you'll want a heating system. In the sunbelt of the country, a solar heater is a good option as it costs less to operate, but typically gas-fired or heat-pump versions are more popular. Most pool water heaters tend to be expensive but now they are highly efficient; you still have to run them for long periods of time to heat a pool properly. "To bring the temperature up to 85 degrees in Texas you have to run the heater for 10 to 15 hours," says Chris Polito, co-owner of Pool Environments.