How Do I Choose the Right Pool Filter?

Pool filters are a must-have for your pool system but choosing a new filter can be quite difficult. The criteria for the right pool filter is dependent on your pool size, usage and location. With only a few types of filters out on the market, picking the right filter can still be difficult. 

Why is a pool filter important? 

Pool filters filter out bacteria and other contaminants that are almost invisible to the naked eye. To put this into perspective,  a household dust particle measures at 4 microns with some bacteria measuring to 2 microns.  Although chlorine and other sanitisers work in your pool to kill the bacteria, the pool filter is what actually removes them from the water.

Types Of Pool Filters

There are two  different types of pool filters, let’s have a look at how they vary: 

1. Sand Filters

Sand filters work by ‘scrubbing’ water that is pushed from the pool pump. As sand has sharp, jagged edges; the scrubbing captures the dirt or debris, leaving you with crystal clear water. Sand filters are most ideal for medium to large pool owners as they are easy to maintain and less likely to clog. Depending on your pool system as well as your pool size, we have a variety of sand filters that can cater to your needs. 

 Pros:

• The initial outlay is more expensive than a cartridge filter however the ongoing costs are minimal
• Easier Maintenance
• Sand can endure for five to seven years before replacement 
• Filtration efficiency can be improved using additives and alternate media

Cons:

• The standard media filtration doesn't filter out particles under 20 microns
• Backwashing wastes water
• Requires more flow to filter and therefore less energy efficient.

Filter Media Alternatives 

The standard media used in sand filters is #20 silica sand as it can grab particles that measure 20 microns or larger.  As it cannot capture the smaller particles, you’ll need to stay on top of your pool water chemistry. There are other sand alternatives to the #20 silica standard that you might feel is best for your needs: 

• Zeosand
  This is created from a mineral called zeolite and you only require half as much (in weight) than your traditional sand filter media. The lifespan of Zeosand is similar to Silica. 
• Filter Glass
  This is finely crushed, recycled glass that can attract particles such as iron and manganese due to it’s negative electrical charge. You only require 20% less filter glass than silica and it can filter debris as small as 5 microns. Filter Glass like our Viron Active Glass Media can also last longer than the traditional sand filter media.  

2. Cartridge Filters

Cartridge Filters are typically more expensive than sand filters, although they are still easy to clean and as effective for medium to small pools. It works by the water flowing into the tank and through a plastic cylinder surrounded by pleated polyester filter media and capped on each end. The debris; as small as 10 microns, is captured in this filter and the clean water flows through to the pool. 

The cartridges are energy efficient and inexpensive but will require cleaning by removing it from the tank and spraying it with a hose to remove the debris and dirt. 

Pros:

• The cleaning process uses much less water. No backwashing - simply lift cartridges out and hose them down. This saves water. 
• Can filter out small particles (as small as 10 microns)
• Performs well at lower speeds (perfect for energy-efficient variable speed pumps).
• Best for smaller pools

Cons:

• Slightly higher ongoing maintenance costs
• It can only last anywhere from one to three years
• Need to deep clean cartridges 1-2 times a year.

Picking a filter will ultimately depend on your lifestyle, budget and pool size.  We hope it helps a bit with the different types of filters that are out there. If there is anything further you need, speak to your local AstralPool dealer.