basics pool filters

In part one of this two-part blog series, we went over some of the basics on pool filters, including basic functions, what “microns” are, and how various pool filters create different effective filtration areas for a given pool. There are a few very different kinds of filters out there, and knowing how these will impact your space is important.

At Dolphin Pools & Spas, we can help with all filter questions and concerns for our custom pools and hot tubs. In part two of our series, we’ll go over why different filters have totally different filtration areas, how to choose the proper area size, and why plumbing concerns matter just as much as the filter when it comes to these important functions.

What’s Behind Filtration Area Size

Many pool owners are shocked at the level to which pool filtration area size varies between different filter types. Cartridge filters have massive effective filtration areas, while DE filters and sand filters come with much smaller areas. Why his this? Let’s look at each example to learn more.

  • Cartridge filters: A cartridge inside a cartridge filler is actually just a giant sheet of polyester cloth or paper, folded up accordion-style to fit into a smaller area. It’s designed to pick up numerous bits of debris. Most cartridge filters will have at least two cartridges, and up to four, meaning their effective filtration areas will range from 200 to 600 square feet. This is by far the largest filtration area you’ll get from any filter option, which is why cartridge filters are popular.
  • DE Filters: DE filters use somewhere between eight to 10 grids (also called “fingers”), which are covered in diatomaceous earth (also called DE powder). These fingers are basically fossil dust, and they provide much more limited filtration than cartridges. Their effective filtration area tends to range between 20 and 100 square feet.
  • Sand filters: Sand filters are what their name suggests – a full tank of sand, which is swirled around by lateral pipes at the bottom for filtration. Sand filters have an effective filtration area of just two to six feet.

Choosing Proper Filtration Area

Filtration area should be a big concern as you’re looking for a new pool filter. You can approximate your needs here by matching your pool’s capacity in gallons to the time you’re planning to run the filter each day. There are also many online resources for this sort of thing.

Do remember, though, that the filter’s area does not directly tell you whether the filter is of good quality. Ensure you’re purchasing an item with good craftsmanship and materials, not just looking for the largest filtration area possible and nothing more.

Filter: Only as Good as Plumbing

During filter installation, securing all plumbing is vital. Any plumbing that shifts or moves will decrease the filter’s effectiveness, so be sure you have a plumbing strap and PVC pipe on hand during installation – our pros can help here.

For more on pool filters, or to learn about any of our pool construction or repair services, speak to the pros at Dolphin Pools & Spas today.