How much does it cost to install a swimming pool water filter?

Pool filters are used to clean debris from the water and help maintain a clean pool. For the purpose of this discussion, we will use the average swimming pool size of 19’ for an above ground swimming pool and 32’x16’ for an in-ground swimming pool.

Types of filter

There are three types of swimming pool water filters: sand filter, cartridge filter, and diatomaceous earth (DE) filter. Each filter uses a similar process in that the water is pumped from the pool through the filter. The filter then captures debris and sends cleaned water back into the pool. Using a water filter system is crucial; without it, the water will become contaminated quite quickly. The chemicals you use in the pool basically sanitize the pool to eliminate bacteria and algae and the filter takes care of larger debris particles. Some filters catch smaller particles than others; but all filters are quite capable of filtering your pool water and keeping it clean:

• Sand Filter: it is filled with no. 20 silica sand graded specifically to trap particles and debris. The sand is located in the filter housing and the filter is connected to the swimming pool by hoses; intake and output. This filter traps debris and particles from 20-100 microns.
• Cartridge Filter: this filter is a pleated construction made of polyester fibers that are wrapped around a hard plastic core. It is sealed on both ends to hold the pleats in place. The water flows through the pleats to the core and then, cleaned water is dispensed back into the pool. This type of filter traps debris and particles from 25-100 microns and works best in salt systems.
• Diatomaceous Earth Filter: the filtering agent is a powder made of microscopic skeletons of diatoms. The powder is added at the skimmer and dissolves on the way to the filter housing. The housing has grids inside that are covered with a nylon fabric. The dissolved powder sticks to the fabric. The grids  trap the debris which passes through the powder and then the fabric. This filter traps debris and particles as small as 3-5 microns and works best in chlorine ¹ pool.

The following table provides an average cost for each type of filter. In addition, you will note the pros and cons, which will help you in deciding which filter to use:

Which filter is best for my pool?

Deciding which filter to use with your pool is important. Size is the first thing to figure out. To determine the size of filter you require is simple mathematical calculations:

• Determine volume of your pool (length x width x depth x 7.5 or radius2 x 3.14 x 5.9 for round pools).
• Divide the pool capacity in gallons by the turnover rate: 12 (minimum to meet standard health codes is 2 times in a    24 hour period).
• Divide the gallons per hour by 60 to get gallons per minute.
• Choose a water filter system that matches or exceeds the flow in gallons per minute you calculated.

Example: Average pool = 32’(L) x 16’(W) x 5’(D) x 7.5 = 19,200/12 (1 turnover in 12  hours) = 1600/60 = 26.66 gal/minute. You need a filter that filters about 27 gal/minute.

Above ground pool filters

Many above ground pools come as a complete system which includes the water filtration system too. As you are buying the above ground pool, it would be best to inquire as to what type of filter comes with the system to make sure you are getting sufficient flow and cleaning power. For an above ground pool, there are two types to choose from, sand and cartridge. The cartridge is the most popular. For the averaged-sized above ground pool, it is suggested to use a filter system with a pump ² of 1 HP (horse power); any stronger than that may push sand into your pool if you choose the sand filter or damage the vinyl ³ of your pool.

In-ground pool filters

For your in-ground pool, any type of filter is okay, so the decision is basically done by you. The most efficient is the DE filter, but it is also the most expensive. The next system is the cartridge system which is more reasonable but may take more time and manual labor to clean the filters. The sand filter system is also very popular, but it is the least efficient. Overall, the DE filter is considered the best and can save you problems down the road.

Saltwater pool system

The same principals apply to salt water pools: you can use any of the three types of filters. A sand filter will last 3-5 years depending on the amount of use. The cost to maintain it will be approximately $100 in this 3-5 year period. Clearly, it is very economical to use. The cartridge filter can also be used; expenses with this type of filter are somewhat higher because you need to change the filter regularly. Some filters are very inexpensive ($5) and other can be quite high ($250+). The DE filter is still the best at removing even the smallest particles for salt water pools. 

Labor

Typically, setting up your above ground pool and water filtering system is straightforward. However, if you have trouble, you may need to hire a plumber. Keep in mind that the typical hourly rate for a plumber is $45-$65/hour. It should take about 1-3 hours depending whether you are working from scratch or with a package deal.

For in-ground pools, the water filter system may be more complicated. There will be both plumbing and electrical requirements. These requirements may be included in the contract you have with the business installing your pool. However, if you have to hire a separate plumber and electrician, plan on spending $45-$65 per hour for the plumber and $65-$85 per hour for an electrician. This project should take 1-3 hours.

Enhancement and improvement costs

Pre-filter

A pre-filter or skimmer basket is a net or basket of sorts that catches large debris before it gets to the water filter system. The pre-filter means a longer life for your water filtration system, and less maintenance and cleaning of the filtration system. Pre-filters are very inexpensive ($3-$30) depending on the size and type of skimmer you have.

Automated pool cleaners

Automated pool cleaners can greatly help with keeping your pool free of debris. They are used in conjunction with the filter. There are several kinds of cleaners: suction, pressure and robotic.

• Suction cleaners are easy to use and cheaper ($99-$249) than the other two. They hook up to your water filter pump and randomly move about the pool sucking up debris.
• Pressure cleaners ($199-$599) are powered by the water pressure from the pool return. They are popular because they have a lot of power and work well.
• Robotic cleaners ($264-$4799) are neat little units that vacuum and scrub your pool.

Some brands are more suitable for vinyl ³ and gunite ⁴, so check with your supplier to make sure you get the right cleaner.

Remodeling Terms Cheat Sheet

² Pump: A device used to move air, liquid, or gas by mechanical means

³ Vinyl: A synthetic plastic made from ethylene and chlorine. Vinyl has many applications in the construction industry and it is widely used in sidings, window frames, roofing and gutters, among others

⁴ Gunite: A type of concrete used for building concrete pools, lining tunnels, and structural repair. It is applied by being sprayed through a pressure hose, and produces a dense, hard layer of concrete