How to Choose the Right Filter for your Swimming Pool

Having a swimming pool is a huge one-time investment. However, it also demands the requirement of its pool filtration system to be maintained.

While chlorine and several sanitisers kill bacteria and other pollutants, pool filters on the other hand remove them from the water. In fact, without a proper pool filtration system in place, the swimming pool water will become cloudy within a few days!

This explains why it is important to select the best pool filter—one that is easy to maintain, is durable and traps the maximum number of contaminants.  

 

3 Types of Pool Filters

Pool filters remove contaminants which exist on the scale of microns or one-millionths of a meter. Since these pollutants are in microscopic size, do pool filters really have the capacity to trap them? Read on to find out. 

There are three swimming pool filtration systems:

 

1. Sand Filters

The total filtration area of a sand filter equals the filter itself. As water flows past the filter sand, the contaminants are trapped within the sand filter media while clean water exits the outlet port of the filter.

Once the filter is clogged with dirt and debris, water pressure drops leading to a low flow rate. To clean the sand filter media, water is pushed in the reverse direction (referred to as ‘backwashing’). Then, the filter is shifted to ‘rinse’ mode to prepare it for the next water filtration cycle. 

 

Pros of Sand Filters

• The least costly
• Minimal maintenance time
• Clog slowly
• Last up to 6 to 7 years

Cons of Sand Filters

• Do not capture bacteria less than 20 microns 
• Investment is required in tough sanitisers
• Manual backwashing and rinsing are required
• Increased water pressure decreases filter efficiency

 
 
2. Cartridge Filters

Cartridge filters are efficient, effective, and easy to maintain for small- to medium-sized pools. Within a tank, a plastic cylinder is encircled by a polyester filter fabric and is capped on both ends. 

Water flows into the tank and past the filter. Particles as tiny as 10 microns are efficiently filtered. To clean the filter, remove the cartridge and wash out the accumulated debris.

 

Pros of Cartridge Filters

• Easier to maintain
• No manual backwashing is required
• Work in low water pressure

Cons of Cartridge Filters

• Slow filtration process
• Last only up to 3 years
• Frequency of deep cleaning of filter cartridges increases as the usage period prolonged.
   

 

3. Diatomaceous Earth or D.E. filters

This is the most costly, high-maintenance pool filtration system (yet the most efficient in decontaminating pool water). The total filtration area is between that of a sand filter and cartridge filter. 

Diatomaceous earth filters have grids packed with white powder that’s prepared from crushed fossils of aquatic organisms. The fossils also contain silica and ingredients present in pest control, toothpaste, etc. 

To turn it into an efficient pool filtration system, the white powder is heat-treated. When water pressure builds up, the D.E. filter is backwashed and more D.E. powder is added.  

However, for safety reasons, keep D.E. white powder out of the reach of children and pets. Moreover, when adding the D.E. powder, use a face mask to prevent inhaling the carcinogenic mixture.

 

Pros of D.E. Filters

• Filter the tiniest particles (as small as 5 microns)
• Easy to add via pool skimmer
• Chemical-free

Cons of D.E. Filters

• Costly
• Grids last for 2 to 3 years only
• Annual cleaning is necessary
• Backwashing can be challenging
• Carcinogenic if inhaled for a long time

 

How to Choose the Right Filter for Your Pool

To choose the right filter, begin with:

• Determine the size of the pool—length, width, and depth. 
• Determine the maximum and minimum water flow rate.
• Evaluating the manufacturer’s specifications if the maximum flow rate suits the capacity of the pump in your pool.
• Opting for the largest pool filter that your pump and pool area can easily accommodate. It will reduce the clogging rate and maintenance time.

 

Final Verdict

All in all, sand filters are inexpensive and last longer than other filter types, while cartridge filters are easier to maintain and can efficiently clean pool water. D.E. filters work most effectively in filtering pool water but are costly. 

For more information, feel free to get in touch with our swimming pool filter system specialists.