Everyone wants to see very clean and clear water in their pool. We spend time getting leaves out and adding chemicals, but one of the hardest-working parts of a pool is often forgotten: the filter. It’s the secret hero of clean water. This makes people ask the big question: how often to clean a pool filter? This guide will give you a simple answer, so you can spend less time worrying and more time swimming in a clean, healthy pool.
Why a Clean Filter is So Important
First, let's talk about why you need to clean your filter. Your pool filter is like the kidneys of your pool. It takes out all the tiny, unseen dirt that makes the water cloudy—things like dirt, oils, and dead algae. Good pool filter maintenance is not just for clear water; it's for the health of your whole pool.
A clean filter lets water move easily, so your pump doesn't have to work as hard. This saves you money on electricity and can make your expensive pump last longer. It also helps your chemicals mix in better, so they work better at cleaning the water. A dirty, clogged filter is the main reason for cloudy water and bad water flow.
The Main Rule: Your Pressure Gauge is Your Best Friend
If you want one easy rule that works for all filters, this is it: watch your pressure gauge. This little dial is usually on top of your filter, and it is the best way to know when it's time to clean. It tells you the water pressure inside the filter in pounds per square inch (PSI).
The first thing you have to do is find out your filter's "clean" pressure number. To do this, clean your filter very well and then turn the pump on. Look at the number on the gauge—this is your starting pressure. The main rule for pool filter cleaning is to clean it when the gauge is 8-10 PSI higher than your clean number. A higher pressure means the filter is full of dirt, so it's harder for water to get through.
Cleaning Plans for Each Filter Type
Your pressure gauge is your best guide, but each of the three main filter types has its own cleaning plan and way of doing it.
Cartridge Filters
Cartridge filters clean water using a material that looks like folded paper. They are good at catching small bits of dirt, but they will get dirty faster than other types.
- When to Clean: Clean it when the pressure gauge is 8-10 PSI over its clean number. This usually happens every 2 to 6 weeks.
- How to Clean: You need to turn off the pump, let the air out of the tank, and take out the cartridges. The main way to clean them is to wash them with a hose. You should spray water between all the folds to get the dirt out. A few times a year, you should also deep clean them by soaking them in a special cleaner to get out oils and other tough gunk.
Sand Filters
These filters are very common and easy to take care of. They use special sand to catch dirt. Over time, the dirt builds up and slows down the water.
- When to Clean: This is where people ask, "how often to backwash a sand filter?" The answer is you only backwash when the pressure gauge reads 8-10 PSI higher than the clean number. It's actually bad to do it too often because a little bit of dirt helps the sand catch even smaller things.
- How to Clean: Cleaning a sand filter is called "backwashing." This sends water backward through the filter to wash out all the dirt. It's an easy job that only takes a few minutes. You should also use a special sand filter cleaner once a year to get rid of oils that backwashing can't.
Diatomaceous Earth (D.E.) Filters
D.E. filters clean the water the best. They use grids covered in a special white powder called diatomaceous earth.
- When to Clean: You clean a D.E. filter when the pressure is 8-10 PSI above normal. This usually happens every 1 to 3 months.
- How to Clean: You start by backwashing, just like a sand filter. But after you backwash, you have to add new D.E. powder to the filter. Once a year, you should take all the grids out of the tank and clean them very well by hand.
Why You Might Need to Clean Your Filter More Often
If you have to clean your filter a lot, it is probably because of one of these things:
- Lots of People Swimming: More swimmers mean more sunscreen, oils, and dirt in the water.
- Your Yard: If you have a lot of trees, you will have more pollen and leaves in the pool. A big storm can also wash a lot of dirt into the water.
- Algae Problems: If you just cleaned up algae in your pool, all that dead algae goes right into your filter. Dead algae will clog a filter very fast.
- Pets in the Pool: A dog swimming in the pool adds a lot of hair and dirt, so the filter gets dirty quickly.
How Your Pool Cleaner Changes Things
The type of pool cleaner you have can influence how much work your filter does. A new robotic pool cleaner is a handy machine, so you don't have to clean your filter as much. That's because it carries its own filter bag within. For instance, the iGarden Pool Cleaner has a big filter basket to trap debris, so your main filter stays cleaner longer. It gathers leaves and other large objects before they even get to your main filter. This cuts down the amount of work your pool filter does.
But a suction-side pool cleaner (the type you plug into the skimmer) deposits all the dirt it collects directly in your pump basket and filter. That makes your filter work harder, and you'll likely need to clean it more frequently. An effective pool cleaner is a key component of your pool filter maintenance strategy. The more effectively your pool cleaner captures dirt first, the less your main filter has to do.
Conclusion
So, how frequently do you clean your pool filter? The simple answer is: when your pressure gauge says so. Don't look at a calendar. What you need to do is to inspect your filter's pressure number weekly. When it's 8-10 PSI higher than its clean starting number, it's time to clean it. This will keep your filter clean and is one of the simplest and most significant things you can do to ensure your pool is clean, healthy, and swim-ready.
