Differences Between Sand DE and Cartridge Filter Systems

Find out which one Works Best for You and Your Pool

One question that is constantly being floated around the pool industry is What is the best filter system?  followed up with “How do I choose between sand, cartridge or D.E filter?”

While some pool owners swear by a cartridge filter, others strongly stand by D.E or sand filters. Everyone has a different opinion. The bottom line is that “No one answer fits all.” There are many variables to consider, such as your pool size, location, nature of the water used, water flow rate and much more.

In this article, we don’t drive you to any one type of filter. Instead, we’ll take a closer look at the three main types of swimming pool filters systems, how they work, and analyze the pros and cons so that you can make an educated decision that will suit your specific needs.

Let’s get started!

Before we take a look at individual types of filter systems, let’s take a quick look at some basics:

What do Filter Systems Do?

All filter systems, no matter what type, have one common goal – to clear your water of debris, dirt and other contaminants.

What are the three main types of filter systems?

    • Sand
    • D.E
    • Cartridge

Comparing one model of filter system to another is like comparing apples and oranges. It’s an unfair comparison, as each type of system filters the water using an entirely different process from the others. Let’s take a closer look at each.

Sand Filters

These filters push water through sand that is located in the filter tank. As the water is the sand, dirt, debris and other impurities are filtered out. The clean water, now free of sediments and other debris, is then returned to the pool.

Cleaning the Filter

Sand filters require a process called “backwashing” to remove the trapped debris from the sand in the container. It is a manual process and is necessary to ensure that the filter continues to work at its optimal effectiveness. Additionally, backwashing also helps in reducing the pressure in the tank.

Backwashing means reversing the filtration process. Water is pumped into the filter in the opposite direction using a multiport valve. This causes dust and other dirt particles to rise to the top of the sand in the filter tank. The debris is then flushed out using a waste pipe.

Filtration Media

Silica sand (fine sand) is used as the filtration media in sand filters. Recently, other, alternative materials have been introduced to the market to replace sand, like Zeo-Clear and recycled glass.

Filtration Rate

Sand filters can filter particles up to the size of 20 microns. (FYI, a strand of human hair measures between 30 to 120 microns).

Pros:

    • Relatively low maintenance
    • Filter sand is easy to replace and is inexpensive
    • It can efficiently trap particles in the range of 20 to 100 microns. There is new, alternative filter media on the market, like glass, that may be more durable and longer lasting than sand.

Cons:

    • Manual backwashing must be done once every few weeks, to maintain the effectiveness of the filter.
    • Particles smaller than 20 microns aren’t filtered
    • Backwashing can be considered not ecologically friendly as it wastes water, and in some localities this type of filter is not allowed by law.

D.E Filters (Diatomaceous Earth)

Diatomaceous Earth (or DE), is a powder that is formed by grounding up fossilized algae, also known as diatoms. This powder is used for coating a grid in the filter, which then collects all particles and sediments from the pool water. Since this powder is finer than sand, it can filter out particles that aren’t trapped by a sand filter.

Just like a sand filter, this one is also cleaned by the process of backwashing. Small amounts of the DE powder are retained in the filter, even after backwashing, so annual cleaning of this filter by professionals is recommended to keep your pool sparkling clean.

Pros:

    • Filters even the tiniest particles out of the water – up to 5 microns
    • Provides the cleanest and most clear water

Cons:

    • The initial cost of this filter is a bit higher than other models
    • Disposing of used DE powder is messy and a difficult job
    • Backwashing is a labor-intensive manual process, and like sand filters, can be considered not ecologically friendly due to water waste. These filters may not be allowed in your locality.

Cartridge Filter

As the water flows through the cartridge, the fabric catches all dirt, dust and other debris, and clean, clear water passes back into the pool. Instead of backwashing, you can quickly remove the cartridge from the filter tank and rinse it down with a garden hose to remove any accumulated debris.

This type of filter works just like the air filter in your car. Water from the pool is pumped through the filter cartridge, a plastic frame that contains rows of pleated fabric.

Pros:

    • It eliminates the need for backwashing
    • Easy maintenance
    • Filter cartridges are long-lasting, around 2-3 years (with proper cleaning)
    • Can filter even tiny dirt and dust particles

Cons:

    • Finding the right pool filter cartridge replacement can be The replacement has to match the size and specifications of the filter. Exact measurements must be taken to make sure the cartridge will fit in the filter tank.
    • Brand names and models differ; for instance, Pleatco pool filter replacement cartridges model numbers do not match the Unicel or Filbur model numbers. This is why exact measurements are critical.  Cartridges are measured to the 16th of an inch.
    • Though it can filter tiny particles when compared to sand filters, it’s not as effective as D.E filters.

The Bottom Line – Extending the Life of your Pool

If you’re looking for the answer to the question, “how to extend the life of your pool?” then you’ve come to the right place.

Choosing the right filter system that matches your pool size and requirements is a crucial step in enjoying your pool for years to come. With that said, finding the right filter system depends on several factors like usage rate of the pool, available time for maintenance, current equipment setup and much more.

We hope that by understanding the workings of each type of filter system, and their pros and cons, you can pick the right type for you and extend the life of your pool, helping you to enjoy crystal clear and sparkling water forever.

Happy Swimming!