How To Select A Pool Filter

How To Select A Pool Filter
How To Select A Pool Filter

How To Select A Pool Filter? Hello. Welcome back to our Pool Equipment Selection Series.

We’ve already walked you through the process of sizing of the pump.

The next step will be to select the type of filter that can handle the size of the pool and the pump.

There are three filter types common on residential pools and are Sand, Cartridge, and DE. each has its pros and cons.

We will talk you through the basics of each then dive into the finer points.

We’ll start with the most common Sand Filters.

These are the most popular filter found in backyards today.

They’re known for being the least expensive as well as being easy to maintain.

A #20 Silica Sand is used as the filter media to sift your pool water clean.

That’s right, Rob. The Sand Filter’s order of operation is pretty simple.

The filter tank is filled halfway with sand, allowing water to filter down through it where it is then collected by an array of laterals.

Yes, like a little fingers?

Little perforated plastic fingers.

Yes. Exactly.

There are two types of Sand Filters.

Top Mount and Side Mount.

This is determined by where the valve is mounted to the tank.

Top Mount, Side Mount.

How To Select A Pool Filter-top mount sant filter compare side mount sand filter
How To Select A Pool Filter-top mount sant filter compare side mount sand filter

I think I missed that. One more time.

How To Select A Pool Filter

Top Mount, Side Mount.

Got it.

All right.
Top Mount Sand Filters are usually cheaper than Side Mount but the Side Mount is more convenient when it comes time to change the sand.

The reason being is that on Top Mount you have to disconnect the pipes in order to remove the valve. On a Side Mount Filter, you don’t need to however, a Side Mount will take up more space on the equipment pad.

If space is limited, go with a Top Mount.

Now, Sand Filters are the least efficient when filtering your pool water, because they can only catch dirt particles around 20-40 microns wide.

If you’re a pool water aficionado /N you will want to look for one of the other options.

Like the Cartridge Filter.

Like this bad boy, right here.

The Cartridge Filter is quickly becoming the favorite for new installations,because it takes up the least amount of space.

It’s easy to clean, and it filters down to 10 microns, which is half a size of what a sand filter can catch.

You’ve been studying Cartridge Filters are made in either single or quad-style.

The Single Cartridge has one filter element, that can range from 25 to 200 square feet of filtering material.

These types are great for small to medium sized pools that have lighter bather loads.

Yes. You know, if you like to be a lone wolf, swim by yourself.

Or you’re just mean to people and they don’t like to be around you.

Yes, I’m a loner, dotty.

The Quad or Four-Cartridge Filters are designed for medium to large pools that expect more debris.

If you have a smallish pool but still plan on a few parties,consider getting the Quad Cartridge.

Quad, like the Four Horsemen?

Yes, I think the Four Horsemen would probably demand a Quad Cartridge


Especially Arn

Yes. Definitely Arn. Yes

Or Ric in his heyday

Oh, the Nature Boy?


It also allows you to go longer between cleanings without sacrificing water clarity.

Speaking of water clarity, last but not least we have the DE or Diatomaceous Earth Filters which are the Cadillac of pool filters as they can catch particles as small as 1-3 microns.

These filters use DE powder which is fossilized shell of diatoms a type of ancient algae.

So, I guess, algae is kind of good for you pool in some ways.

As long as it’s dead for a million years.


Okay. The DE powder is introduced to the filter by pouring it into your skimmer.

The powder then coats the fiber-covered grids and as your water passes through “Voila”, no more dirt. Now, that covers the three different types of filters.

Now let’s take a look at filter sizing.

To prevent excessive cleaning, we suggest sizing your filter properly or better yet, oversizing your filter.

The two factors you’ll want to consider are designed flow rate and turnover capability.

In our pump example we used a pool that was 23,000 gallons.

In order to accomplish the eight-hour turnover rate the pump must push 48 gallons per minute.

Using those numbers, we need a filter with a design flow rate of over 48 gallons per minute and a turnover capability greater than 23,000 gallons.

Now remember, when you oversize a filter, you are helping yourself in two ways.

One, you are able to go longer between cleanings.

And two, you put less stress on your filter and your pump allowing them to last longer.

Yes. And before we close up filters we should touch on the two types of filter valves used on Sand and DE Filters; Slide and Multiport.

Now, this on the screen is a Multiport Valve, which is more common than its counterpart, the Slide Valve.

This is due to its versatility.

The Multiport Valve has up to eight settings, but we will stick to the more common ones, which are Filter, Backwash, Rinse, Recirculate, and Close.

The Filter setting is normal cleaning cycle of your pool water.

The Backwash setting is the cleaning cycle for the filter.

It works by reversing the flow of water through the tank.

Now, after the Backwash comes the after-backwash, AKA the Rinse.

Because backwashing can leave dirt in your pipes,we need to find a way to flush it out before returning the filter to regular filtration

The Rinse returns the water flow to normal patterns,going through the filter but still directs water through your waste.

Then we have Recirculate which allows you to run your pump in order to circulate the water while bypassing your filter media

You would use this setting if you were adding a chemical that requires the filter to be bypassed or let’s say there was a crack in a filter.

You could place the filter on Recirculate and keep the water moving.

And finally we have Closed.

Now, you would only use that if you want to stop water flow from getting past your filter.

For example, if you need to service something down the line like a Chlorinator or a Heater.

And this slender guy on the screen is a Slide Valve, no, not me, the Slide Valve.

Slide Valves are designed for Side Mount Filters.

They only have two positions: Filter and Backwash.

Slide valves are mainly used on eqipment pads with restricted space or if the pool owner prefers a simple setup.

Well Rob, I think that just about covers filters.


Please enter your comment!
Please enter your name here