What Are the Different Types of Pool Filters Available?

There are three different types of filters available for in-ground pools. The three types are sand filters, diatomaceous earth (DE) filters, and cartridge filters. Each has its advantages and disadvantages. The type of filter to use depends on the pool owner's needs in terms of price, amount of maintenance required, and other location-based factors.

Before we go into the details of the different types of filters, it is important to first discuss what a filter does and why it is so important to pooling. Filters are machines connected to the pool's plumbing network. When the water is pushed through, it will pass through the filter, trapping dirt and debris inside. Clean water flows back to the pool through the outlet pipe. It runs in a loop as long as the system is on. Most pool owners run filters for 6 to 12 hours per day, depending on the type of filter and the usage of the pool.

This is one of the oldest technology and the cheapest filters you can buy. If you look at most older swimming pools, unless they have been upgraded, you will find that they have sand filters installed.

In the sand filter, there is a tank with a specific amount of sand, depending on the size of the tank. Sand is the medium that goes into the tank. Only use special sand intended for the swimming pool industry. The filter works by water flowing through the tank from top to bottom. The tank is about 75% sand and 25% free space. When the tank fills the pool with water, it passes through the sand and filters out any microns that are large enough to be caught by the sand. This dirt and debris will remain in the tank until the entire system is backwashed. The filtered water will then be pushed back into the pool.

Sand filters usually have a multi-port valve, which allows the filter to use three to six functions. During normal filter operation, the valve will be set to filter mode. This is how filters are set most of the time.

There's also a backflush mode that enables homeowners to connect a hose to the filter to expel all dirt and debris trapped by the sand. What this basically does is flow the water through the filter from the bottom to the top; this will force any debris collected from the filter into the discharge hose.

The sand inside is generally replaced every three to five years, depending on the length of the swimming season and how well the pool is maintained. This has to be done because the water runs back and forth on it and the grains of sand get rounder, locking them together. This will result in poor filtering.

This filter works similarly to a sand filter. It differs in the filter media used. Inside the DE filter is a set of what is commonly called a grid or finger. These fingers are coated with DE powder, which is made from crushed shells and the external silica secretions of tiny sea creatures called diatoms. When water flows through these fingers, they capture most of the dirt and debris at a much lower micron-scale than sand filters. It captures smaller and finer particles for better water purification. This provides better water clarity and makes swimming safer.

The DE filter must also be backwashed. Unlike sand filters, when you backwash, a lot of DE has washed away and lost. After backwashing, you will have to add more DE powder to charge the filter.

You have to be careful with DE. It is an ultrafine silicate that can be a health hazard. There is some evidence that DE can cause lung problems if inhaled, and skin irritation if not used and handled properly. In New Jersey, it is classified as a hazardous substance and regulated by the Occupational Safety and Health Administration (OSHA).

Some townships require separation canisters so that used DE can be placed in a canister and disposed of properly, rather than being discharged onto the street or property. DE filters must be disassembled every year and fingers must be cleaned and degreased. They are made of cloth mesh material which can adsorb DE powder very well. Contaminants such as body oils, sunscreen, and algae can all collect on the material.

While DE filters may be the best filters when it comes to purifying water, they do require more maintenance than any other type of filter. A DE filter may be the second most expensive filter provided by the pool builder, or the second most expensive filter purchased by a homeowner as an upgrade to replace an old filter. All of these are factors you need to consider when considering purchasing a DE filter.

Cartridge filters are one of the most popular types. There are many kinds of them. There are single-element cartridge filters and multi-element cartridge filters. Multi-element types typically contain two to four cartridges. Pool builders typically install a pool with a multi-element filter. Quality pool builders trying to create the easiest-to-maintain pools often install a four-barrel filtration system.

In a cartridge filter system, the cartridge filter traps debris. Each can come in a variety of sizes, from small, medium to large, depending on the size of the pool. They are usually made from spun polyester that is pleated and wrapped around a heavy-duty plastic or PVC core and bonded at both ends with heavy-duty rubber plastic.

Water flows from the outside of the cartridge to the center core and the pleats in the cartridge catch dirt. It is designed to force water through the folds. The cartridges have a high surface area, so maintenance is greatly reduced. In an in-ground swimming pool that runs 12 months of the year, the filter must be disassembled and cleaned 2 to 3 times a year.

Effectively cleaning the ink cartridges usually takes about an hour to an hour and a half. This involves taking them apart and cleaning all the elements. Once the cartridge is removed, the hose will pick up most of the heavy dirt and debris. Cartridges must be degreased at least once a year due to the buildup of body oils, sunscreen, hair care products, and accumulated algae. If you do not do this, the ink cartridges will not perform optimally.

With good maintenance, a cartridge can last four to eight years before it has to be replaced, and the best news is that it's easy to replace. All you have to do is pull out the old one and put in the new one. Once you replace them, it will work as if you had a brand new filter. The filter will be fully operational and at full capacity. Cartridge filters never require backwashing, sand or DE media, and a knockout tank.

The most common type of filter you will see is a sand filter. They will effectively clean the pool for years with few problems. They are the cheapest filters on offer, so are usually included as part of a basic pool package.

DE filters are used less frequently because they are very maintenance-intensive. Advanced pool builders often encourage the use of cartridge filters to make the pool easier to maintain. Most pool companies will allow you to pick the filter that works for you. Sometimes a cartridge filter is standard, and other times there may be an extra charge for it. Whether this is correct depends on the specific pool builder.

The decision on which filter to use really comes down to the level of maintenance the homeowner wants to perform and what they think is most important to them. Is it decontamination, maintenance, or long-term costs? This will vary from person to person. If you are not sure how to buy the right filter for your pool, please contact us.

MAYGO POOL is a professional custom pool filtration systems manufacturer, focusing on providing professional technical solutions for residential and commercial swimming pools. At present, we have provided swimming pool solutions to thousands of customers in North America, South America, Europe, Australia, etc.