What Swimming Pool Filter is the Best?

• Posted In:
Pool Filters

Saturday, May 1st, 2010

Wow, what a topic!  This is a common head scratcher for most swimming pool owners and can even be difficult for some of the newer swimming pool professionals to answer.  When I first began my employment in the swimming pool industry, I worked for a service route, cleaning pools and trying to absorb anything I could about the pool business.  Although my observations helped, it was a combination of building on my experience and taking classes that really strengthened my understanding of swimming pool filtration.  It wasn’t until then that I truly began to grasp the difference between the three major types of filters, and how each serves a distinct and different way of filtering water.

As I may have implied, the question is not as easy to answer as some may think.  In order to determine which filter will be the best fit, you have to ask yourself a series of questions.  Only by comparing and measuring the particular functions of each pool filter will you be able to establish which is optimal.  You need to consider replacement and maintenance costs, maintenance time, cycle run time per day, dirt capacity, and micron removal.  What is the condition of the water you need to filter? Is it a pool, spa, fishpond, decorative pond, or a number of the previous?  Taking all of these into consideration, let’s cover some specifics that will help you make a more informed decision.

Purpose of the pool filter:

To begin, let’s discuss the purpose of a pool filter in the circulation system.  The swimming pool filter is only one of many key elements to great water clarity.  It removes physical dirt and debris particles from the water.  The filter will then trap and contain the dirt until it is either cleaned or backwashed.  Backwashing is the process of reversing water flow to remove large amounts of dirt or sand particles from the filter grids.

What is the key to good water filtration?

Speed. The slower the water flows through the filter, the greater the filtration becomes.  Extremely high water flow (high filter pressures) could force debris through the filtration element back into the swimming pool, whereas lower water flow through the filter will place the debris onto the filter median and allow for easier cleaning.  The debris will also help capture smaller particles.

What is filter efficiency?

There are three main factors to consider when determining what makes a pool filter efficient.  The size of the particle the filter can capture and hold, how long it can adequately perform between cleanings, and the ease of maintenance.

The particles a filter can hold are measured in microns.  A micron is 1/1000 of a millimeter.  To put this into perspective we have laid it out below.

* Cartridge Filters – Filter up to 10-15 microns (a single grain of beach sand is 90-100 microns).
* Diatomaceous Filters (D.E.) Filters – Filter up to 5 microns (1/10th the width of a human hair).
* Sand Filters – Filter up to 20-40 microns.

Cartridge Filter:
Pros:
* Filter maintenance is easy.
* Can often be less expensive than its competitors.
* Great for small swimming pools, spas, or fountains.

Cons:
* Filter is less tolerant to higher operating pressures (works best under low pressure).  Consider using a variable speed pump.
* Because of the above, water cloudiness is more common.
* Middle of the road for filtering smaller water particles.

Cartridge filters are the newest media to the swimming pool and spa industry.  The first cartridge filters surfaced in the early 70’s.  A company manufacturer called Reemay makes many of the cartridge filter fabric material that goes into making up the cartridge filter cells and is specifically designed to trap dirt down to around 15 microns.

Diatomaceous Earth (D.E.) Filter:
Pros:
* Outstanding pool water clarity.
* Finest filter media used for swimming pools.
* Filter tolerance is greater between maintenance.

Cons:
* Filter maintenance is more difficult to service.
* Some city requirements will now allow new pools to have D.E type filters due to servicing requirements.
* Up front costs are typically more.

Diatomaceous Earth filters use a filter powder called Diatomaceous Earth D.E. filter poweder.  This DE filter powder is actually the fossilized exoskeletons of a marine organism call a Diatom.  It is mined from the ground and processed into a fine dust that is used to coat the surfaces of the internal filter grids evenly.  As water travels into the DE filter, the fine pores contained within the powder trap and filter out dirt particles and water impurities.

Sand Filter:
Pros:
* Filter maintenance is easy.
* Oldest form of swimming pool water filtration.
* Commonly found in many commercial applications due to the high GPM capabilities.

Cons:
* Pool water particles are not filtered as finely as Cartridge or D.E. filters.
* Sand filter maintenance frequency is typically greater.

Dirty pool water enters the sand filter through a distributor, which evenly dispenses the water down over the top of the bed of sand.  The dirt is typically captured in the first 4″ of the sand bed.  The water then continues through the rest of the sand to the laterals, where clean water exits the sand filter. FYI: NO, YOU CANNOT USE BEACH SAND – haha, I know you were thinking that!  Make sure you use #20 silica sand, this is required for sand filters.

Remember, crystal clear water clarity doesn’t stop with having the best swimming pool filter.  You also have to consider all the factors including good water chemistry, properly sized pool pump, duration of filtration cycle and frequency.

I hope this answers a few of your questions about swimming pool filters and each of their individual functions.  Remember, you can always consult our local swimming pool professionals list on our home page for more advice on swimming pool equipment maintenance!

Contact Reliable Pool Solutions for any questions or service!

Best Regards;

RPS Blogger