New coupons for Poolman services are now available. In Phoenix and San Diego, you can save $50 on a new diatomaceous earth or cartridge filter. Both have unique pros and cons. Let's go over the three different types of filters so you can decide which is right for your pool.

DE Filter
A DE filter uses diatomaceous earth – the fossilized remains of diatoms – to filter your pool. According to Pool Center, it can collect particles as small as three microns because of the how fine this powder is. The DE acts like a filter in itself as it is made up of microscopic hollow shells.

When the powder is added to directly to your pool's skimmer, it reaches the grid – a nylon fabric. The DE then covers the grid and it only allows water to get through, trapping the dirt on one side. When the filter cannot clean anymore – which should be about a year – you may notice a slower flow rate. At this point, the system is backwashed and you add more DE powder to the skimmer.

Diatomaceous earth filters give the cleanest water out of the other filter options, according to Pool Supply World. Along with the cleaner pool, you may also have to pay a higher price, but DE powder itself is relatively cheap compared to other pool chemicals.

Cartridge Filter
Cartridge filters are popular for spas and above ground pools. These filters trap particles down to five microns in size. Cartridge filters consist of a screen made of polyester – this collects the dirt – and are placed in a small tank. The cartridges need to be rinsed and cleaned when the pressure in the tank rises too high, which occurs around every six months. Cleaning is as easy as using a hose and doesn't require backwashing.

These filters have a large amount of surface area and therefore work best at slow flow rates. This makes cartridge filters more energy efficient than other filtration methods and it utilizes less water. The downside is that these filters need to be replaced every three to five years. Good news is that your local Phoenix or San Diego pool service can easily do this for you.

When determining which pool filter works best for your pool, consider the types of debris your pool collects. A DE filter will work better on smaller particles while a cartridge filter will work more efficiently with larger types of debris.