At the same time that you're deciding on the size and shape of the new pool you're planning to have installed in your yard, you also need to spend some time considering the type of filtering system you would prefer. There are basically three different types: sand, cartridge, and diatomaceous earth. Each of these types of filters have their good points and their downsides, so it's best to consider all aspects of filtering prior to making a decision which type of system to use in your pool.
Sand filters are very popular, which is probably because they are inexpensive to buy and easy to maintain. Unfortunately, they are also the least effective of the three different types. This kind of filtration system pushes the water through the sand which removes most of the contaminants. As you can imagine, though, this system has the drawback of allowing some particles to recirculate back into the pool water making it a much less efficient answer to keeping your pool clean.
Many people choose cartridge filters for their swimming pools, because they clean the water well, and if you buy the more expensive type, they can last for many years. No matter whether you purchase an inexpensive cartridge filter or a higher-quality one, they will both require regular maintenance. As water passes through them, the particles in it are trapped in the filter. These particles build up in the filters, and if they aren't cleaned out, there will be no more room, so contaminants will start passing right on through them and back into the pool water. With an inexpensive filter, this means you will need to replace it. If you have a more permanent filter, you have to remember to remove the filter and clean it with your garden hose a couple of times during pool season.
Diatomaceous earth filters (DE) are considered to be the finest solution to cleaning pool water. These are made of a substance mined from the earth which is made up of the fossilized skeletons of tiny organisms. DE filters consist of a filter housing which contains grids. When the DE is poured into this housing, it coats the grids where it will stay and act as a sieve for microscopic particles. DE can filter out much smaller particles than either sand or cartridge filters, so it is much more efficient as a filtering medium.
The downside of DE water filters, as might be expected, is that they are the most expensive of the three types of swimming pool features that are available. However, they can filter out debris as small as 5/1,000 of a millimeter; therefore, if it's really clean water you're looking for, DE filters are your best choice. In order to cut the cost, some people attempt to add some diatomaceous earth to their sand and cartridge filters, and although this is no substitute for a real DE water filter, it will still increase the efficiency of the filters.
