If your pool’s not circulating, it’s fermenting. A bit dramatic? Maybe. But also, not wrong.
Water without filtration is like a cup of soup left in the sun. Give it time, and it’ll tell you exactly what grows in warm, stagnant liquid. And while many people obsess over chlorine levels or shock schedules, the truth is this: your pool filter is doing most of the heavy lifting.
Hayward is one of the biggest names in the pool industry. Their filters are everywhere, in backyards, hotels, spas, and DIY plunge pools cobbled together with questionable plumbing. But here’s the thing most people don’t realize: if you don’t understand how your filter works, you’re probably not using it right. Or worse, you’re making it work harder than it should.
In this post, I’ll walk you through the guts of a Hayward filter: what it does, how it does it, what types exist, and how to know when it’s begging for attention. Whether you’ve got a sand tank the size of a wine barrel or a sleek cartridge setup humming in the corner, this is the knowledge that keeps your water clear and your maintenance time low.
Key Takeaways
- A Hayward filter removes debris and particles from your pool water to keep it clean and safe.
- There are three main types: sand, cartridge, and DE (diatomaceous earth), each with unique pros and maintenance needs.
- Sand filters are low-maintenance and effective for large pools.
- Cartridge filters offer finer filtration and use less water, but require regular cleaning.
- DE filters deliver the clearest water, filtering down to 2 to 5 microns, but need more maintenance.
- Monitor your pressure gauge, rising PSI means it’s time to clean or backwash.
- Pairing the right pump with the right filter is essential to avoid overloading the system.
- You can’t run a standard pool without a filter, but natural pools are a different story.
- Small upgrades like multiport valves, timers, or solar setups can improve efficiency and reduce energy use.
- Filter choice affects everything from water clarity to chemical usage, so choose based on your pool’s needs and how hands-on you want to be.
What Role Does a Pool Filter Play in Your System?
It’s the organ you forget exists until something goes wrong. Your pool filter is where the dirty work happens. It removes gunk, dead bugs, skin cells, algae spores, dust, leaves, and all the micro-debris that chlorine doesn’t destroy.
Without a functioning filter, even the best chemistry turns into a guessing game. Filtration and circulation are the real MVPs. The pump pulls water in. The filter traps unwanted particles. The water returns cleaner, clearer, and safer.
Skip this step, and your pool becomes a chemistry experiment gone wrong. Smell that weird metallic tang? That’s a neglected filter.
Switch to Sustainable, Smarter Water Systems
The Hayward Filter Types & How They Work
Hayward builds three main types of filters: sand, cartridge, and DE (diatomaceous earth). Each works differently, but they all do one thing, trap particles you don’t want floating around in your swim zone.
Sand Filters
Water enters a tank filled with fine-grade pool sand. As it flows through, dirt and debris get stuck in the sand bed. Clean water flows out the bottom and returns to the pool.
Eventually the sand clogs with debris, and the pressure inside the tank rises. That’s your cue: time to backwash which means reversing the flow to flush out the crud. Easy, effective, and a favorite for large, standard-use pools.
Cartridge Filters
No sand here. Instead, the water passes through a pleated filter cartridge which is basically a fancy sponge with lots of surface area. Dirt sticks to the pleats. When pressure builds, you remove the cartridge and hose it down.
Cartridge filters are known for fine filtration, quiet operation, and lower water waste since there’s no backwashing. But they need regular manual cleaning.
DE Filters (Diatomaceous Earth)
These are the overachievers. DE filters use grids coated with diatomaceous earth, a fine white powder made from fossilized algae. Sounds weird. Works beautifully.
They trap the smallest particles of all three types (down to 2 to 5 microns). Great for ultra-clear water, but they’re more work: you need to backwash and recharge with fresh DE regularly.
How a Hayward Filter Works, Step by Step
- Water enters the skimmer or main drain.
- The pump pulls it into the system.
- Water is pushed into the filter tank under pressure.
- Inside, debris is trapped by the sand, cartridge, or DE grids.
- Clean water exits and flows back into the pool through return jets.
Your pressure gauge is the window into this system. If PSI rises significantly (usually 8 to 10 psi over the baseline), the filter media is dirty. That’s your signal to clean, backwash, or replace.
Why Hayward Filters Are Popular (and What to Watch Out For)
People like Hayward because they’re reliable, well-supported, and not overly complicated. Replacement parts are easy to find, and they make filters for everything from above-ground pools to commercial installations.
But even a good system breaks down when:
- The filter is undersized for the pump
- The sand is too old (yes, sand wears out)
- You skip maintenance for months
- You use the wrong DE powder or filter cartridge
One common mistake? Pairing a high-powered pump with a tiny filter. That just blasts debris through instead of filtering it. Think balance: flow rate, filter size, and your pool’s needs all matter.
Maintenance & Troubleshooting for Hayward Filters
Let’s get practical. Here’s how to keep your Hayward filter running like it should:
- Check the pressure gauge weekly. Learn your system’s normal pressure and watch for rises.
- Backwash (for sand and DE) when pressure rises 8 to 10 psi. Follow Hayward’s guide to avoid overdoing it.
- Clean cartridges every 2 to 4 weeks, depending on use. Remove them, hose them down, let them dry.
- Replace media when worn out. Sand should be changed every 3–5 years. Cartridges? Once or twice per season. DE? Top up after every backwash.
- Look for leaks or cloudy water. That’s often a broken O-ring, a clogged line, or a failed seal inside the tank.
Hayward’s own filter knowledge base is a useful reference point if you’re stuck.
When You Consider Running a Pool Without a Filter
Short answer: don’t. Long answer: only if you’re doing something very unconventional.
A standard chlorinated or saltwater pool absolutely needs filtration. Without it, water stagnates, debris builds up, and chemicals become ineffective. You’ll spend more on chlorine trying to compensate for what the filter isn’t doing.
However natural pools and regenerative aquatic systems are different. These systems use plants, gravity, biofilters, and microbial ecosystems to do what filters normally would.
So if you’re trying to run a pool with no pump or filter, you need:
- A well-designed flow layout
- Biological filtration (like planted reed beds)
- Regular manual maintenance
It’s not “easier.” It’s just a completely different approach.
Upgrading or Optimizing Your Hayward Setup
Already have a Hayward filter? Here’s how to make it work better:
- Match your pump flow rate to the filter’s design. Don’t overpower or underdeliver.
- Add a multiport valve to simplify maintenance.
- Install a timer or smart controller to run your pump during optimal hours.
- Consider solar power or off-grid setups if energy use is a concern.
- Use clarifiers or enzyme-based cleaners to reduce strain on your filter.
Small tweaks can make your system quieter, more efficient, and cheaper to operate. That’s worth doing, especially if your pool runs all season.
Understanding Micron Ratings (Nerdy But Important)
- Sand filters trap particles down to about 20 to 40 microns.
- Cartridge filters trap particles around 10 to 15 microns.
- DE filters catch things as small as 2 to 5 microns.
For context: a human hair is about 70 microns wide. Bacteria? Around 2 microns. So filter choice affects water clarity in a big way.
That doesn’t mean you always need DE. It just means know what you’re dealing with, and what your goals are.
Do Natural Pools Need Filters?
Short answer: no, not in the traditional sense. Natural pools use biological filtration instead of mechanical systems like sand or cartridge filters.
Instead of pressurized tanks and chlorinated water, they rely on:
- Regeneration zones with aquatic plants
- Gravel beds and biofilm for microbial filtration
- Passive flow systems that mimic natural water movement
There’s still filtration, but it’s alive. Literally.
Water moves through planted zones where microbes and plants consume nutrients, break down contaminants, and outcompete algae. The result? Clear, chemical-free swimming water that feels more like a spring than a city pool.
Of course, it requires good design. Flow, slope, volume, plant choice, all of these matter. You’re not just building a pond. You’re building an ecosystem.
If you’re wondering whether you can ditch the pump-and-filter model entirely, and design something regenerative from the ground up, this is the path. And yes, we help people build these.
Conclusion
A Hayward filter isn’t magic. It’s plumbing, pressure, and physics working together to keep your pool from turning into a frog-friendly algae farm. But like any system, it only works as well as it’s maintained. And it only gets maintained if you understand what it’s doing behind the scenes.
Now you do. You know the difference between sand, cartridge, and DE. You know what happens when pressure spikes. You know that clean water isn’t just about chemicals, it’s about circulation, filtration, and giving your system a chance to do its job.
At Oásis Biosistema, we take this thinking a step further. We design water systems like natural, mechanical, hybrid, that work with ecology instead of fighting it. So if your Hayward setup is feeling tired, oversized, undersized, or just underwhelming? Let’s redesign it with intention. Let’s make your pool not just cleaner, but smarter.
Start with filtration. Build a better system from there.
FAQ
How does a Hayward filter work?
A Hayward pool filter works by pulling water through the pump and pushing it into the filter tank, where sand, cartridges, or DE grids trap dirt and debris. Clean water returns to the pool through the return jets. Regular backwashing or cartridge cleaning keeps the filtration system efficient and balanced.
How many hours a day should I run my Hayward pool pump?
Most pools need the Hayward pump to run 8 to 12 hours per day, depending on pool size, bather load, and climate. The goal is to circulate the entire pool volume at least once daily. Running the pump during warmer months or high-use periods may require longer cycles for proper filtration.
How to tell if a pool filter is working?
A pool filter is working properly when water stays clear, pressure remains within the normal PSI range, and the return jets feel strong. Rising PSI indicates the filter is trapping debris and may need cleaning. Cloudy water, weak flow, or low PSI are signs of poor filtration or equipment issues.
Are Hayward pumps self-priming?
Yes, most modern Hayward pool pumps are self-priming. They are designed to automatically purge air from the system and draw water from the pool once started. Proper installation, especially correct water level and airtight plumbing, helps the pump prime quickly and ensures stable, efficient circulation.
