When to Backwash Pool Filter in AZ: A Guide

E-Konomy
Aug 1
5 min read

In a desert climate, maintaining a healthy and clean pool requires more than chemicals to keep it clear and clean. It also needs a good filtration system. Those who have a sand or diatomaceous earth filter must backwash them. This means pushing water through the filter to clean the sand or diatomaceous earth, as it will be filled with trapped debris.

Knowing when to backwash a pool filter in AZ is important, and this guide is meant to help pool owners understand when it's time and how to to it. It is also important to know what are the different types of pool filtration systems in AZ?

What Is Backwashing?

Backwashing is the process of reversing the flow of water through a pool filter to flush out the accumulated dirt, debris, and other contaminants. It is a type of deep cleaning that is required for both sand and DE filters.

When a pool pump and filter is working correctly, the pump pushes pool water through the sand or DE, which then traps the particles. Overtime, this debris backs up and clogs the filter, which decreases the flow of water and the efficiency of the filter. Backwashing clears this backup and it helps the filter work better. A clean pool filter keeps the water looking clear and clean. Local Tucson pool care professionals may be consulted for more information about backwashing.

Types of Pool Filters That Require Backwashing

In Arizona, there are three main types of filters; sand filters, diatomaceous earth filters (DE filters), and cartridge filters.

Sand Filters

Sand filters use fine-grade silica sand to trap debris. As the debris begins to accumulate, the sand becomes hard and compact, which reduces the flow rate. Pool owners who have this type of filter must backwash every 2 to 4 weeks to keep the pool running smoothly.

Diatomaceous Earth (DE) Filters

A diatomaceous earth filter contains a grid that is coated with a fine powder called diatomaceous earth. This combination can trap particles as small as 2 microns. Pool owners with a DE filter must backwash their filters every 4 to 6 weeks, on average.

Cartridge Filters

Cartridge filters do not require backwashing and are cleaned by manually removing and rinsing the cartridge, then placing the clean cartridge back into the filter.

Why Backwashing Is Especially Important in Arizona

Arizona has a climate that brings unique challenges to pool owners. Because of this, it's common for Arizona pool owners to have to backwash more often than in other parts of the country. Things like dust storms, intense sunlight, and dry conditions create more sand, dirt, and debris.

Signs It’s Time to Backwash the Pool Filter in AZ

Backwashing is part of a routine pool maintenance schedule, but sometimes the filter must be backwashed before it's normally time. Here are some of the signs pool owners should look for:

1. Increased Pressure on the Filter Gauge

Almost every filter system has a pressure gauge. As a general rule, if the pressure rises more than 8-10 psi over the filter's clean pressure, it is time to backwash.

2. Reduced Water Circulation

If a pool owner notices a drop of water flow from the returns, it can indicate a clogged filter and it needs to be backwashed.

3. Cloudy or Dirty Water

If the water is dirty or cloudy, and the water chemistry is normal, it's likely that the filter is not effective any longer.

4. Unusual Noises from the Filter

A clogged filter may also make strange noises. If the skimmer basket is clean, and there are still noises, it could be due to restricted water flow because the filter needs to be cleaned.

5. Recent Dust Storm or Heavy Winds

After a haboob or strong wind event, filters often become overloaded with debris and require immediate backwashing.

How to Properly Backwash a Pool Filter

Many people in Tucson work with a company like E-Konomy Pool Service & Supplies for daily maintenance, and backwashing is part of the maintenance process. However, others do the backwashing themselves.

Here is a general step-by-step process to backwash a sand pool filter:

Turn off the pool pump.
Set the valve of the filter valve/backwash valve to “Backwash.” Make sure the filter position is in a good place, away from the house, as water will flow out and soak everything.
Turn the pump back on. Let it run for 2–3 minutes, or until the water in the sight glass or backwash hose runs clear. You can also use the drain plug to let more water out until you see clean water glowing through.
Turn the pump off again.
Set the valve to “Rinse” and run the pump for 30 seconds to settle the sand.
Return the valve to “Filter.”
Turn the pump back on and check pressure gauge levels.

Here is a general step-by-step process to backwash a DE pool filter:

Turn off the pump.
Set the valve to “Backwash.”
Turn the pump on for 2–3 minutes or until water runs clear.
Turn off the pump.
Return the valve to “Filter.”
Recharge with DE powder through the skimmer (per manufacturer’s instructions).

Note: Always refer to the manufacturer’s manual for your specific filter model.

Tips for Backwashing in Tucson’s Water-Conscious Climate

Arizona frequently faces water shortages and drought conditions, and pool owners should take care to minimize the amount of water they use. To do this, consider these best practices:

Only backwash when necessary, not on a fixed schedule.
Install multiport valves with sight glasses to monitor clarity.
Use eco-friendly filtration media that reduce backwashing needs (e.g., glass media vs sand).
Instead of using a garden hose, consider recycling backwash water to water plants.
If your pool water levels are getting too low after backwashing, add water. If you don't, chemicals, like chlorine, could get out of whack.
Work with a local pool maintenance company.

In Tucson, where water conservation is a community concern, minimizing unnecessary backwashing is both environmentally responsible and cost-effective.

Professional Pool Filter Maintenance in Tucson, AZ

While some pool owners perform backwashing themselves, many prefer to rely on a professional pool maintenance company for regular cleaning and inspections. Professional technicians will do the following:

Monitor filter pressure
Schedule backwashing at optimal times
Handle DE replacement and disposal
Identify early warning signs of filter or pump issues
Help extend the life of the filtration system

In Arizona’s demanding climate, having trained professionals oversee the filtration system ensures year-round clarity and health.