When it comes to cleaning, the cartridge filter is the middle child — not as easy as a sand backwash, but not as messy as a D.E. grid spray-down.

Still, despite the relatively straightforward process, a few tweaks can make this job a little more thorough and a lot faster. And over the course of a year, shaving just five or 10 minutes from a process that is performed hundreds times can literally save a week or more of work.

Tal Millican, a sole proprietor service pro in the Tampa area with 66 pools, puts the matter in terms we can all understand: "The faster I get the job done right, the faster the workday is over and I can get home to my beer," he says with a laugh.

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"Seriously though, time is critical when you're in the service business," he adds. "You really have to do the job right in as little time as possible, so I look for every chance to save time, whether it's cutting travel time on my route (I try to minimize the number of left turns in traffic), or trips back to my truck, or the time it takes to do a job like cleaning cartridge filters."

With time-savings and customer satisfaction top-of-mind, we present these helpful pointers for cartridge filter maintenance.

When To Clean

Not too long ago, cartridge filter assemblies were relatively small and needed to be cleaned more frequently. Then in the early 2000s, engineers at the major manufacturers caught on to the idea that a larger filter would mean more filter area, which would mean they wouldn't have to be cleaned as often. This has helped.

Although larger filters reduce frequency of cleaning, the job still must be done and determining when is the first step: keeping a log of filter pressure differential measurements can make this easy and efficient — once you get in the habit.

All Seasons Pools & Spas in Orland Park, Ill., keeps a log of filter pressure readings on each pool serviced. "This can be done by making a note of the filter pressure in each customer file when opening their pool. This way it can be easily retrieved and referred to as needed, says Dan Lenz, vice president. "Having an archive of this data not only tells you when the filter should be changed, it can also help when troubleshooting problems such as cloudy pool water or a malfunctioning heater.

"For example, if a client calls with a problem, the first thing a service technician should do is open the customer file and ask them to check their filter to provide the pressure reading. If it was 18 psi when the pool was opened but is now reading 32, the next step is obvious, and sometimes the homeowners can do the job themselves.

"This best practice can help a pool service company operate more efficiently, as some homeowners invariably seem to call with water clarity issues right before a big pool party or a long weekend. Therefore, it is great to be able to solve these types of problems over the phone rather than trying to squeeze them into a service technician's busy schedule," he says.

"We are diligent in keeping a log of all of our clients each time we service their pools. One of the most important figures we note is the initial psi on the gauge at the top of the filter tank. In fact, our technicians log 40 to 50 items on their mobile device when servicing a client's pool which immediately gets entered into their client file in our business management software."

When To Replace

It's easier to replace cartridge media than it is to clean it, and that's a good thing, notes Rich Tarricone, owner of Aquatic Pool Systems (Sarasota, Fla.) and winner of the 2011 Pleatco Perfect Pool Guy award, because everybody likes to start fresh.

"In replacing the media you're getting rid of any biofilm that could inhabit that filter," he says, "which is a plus for many pool owners. Also, people moving into new homes with a pool, they like that. They want to replace the filter so they're not swimming in anyone else's biofilm or filtered waste."

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Tarricone replaces cartridge media in his Florida pools on a regular basis just to be proactive, but over time any cartridge filter media will develop a hole or tear in the fabric or become hopelessly clogged, forcing replacement.

One of the most common causes of early filter death is clogging due to embedded pool gunk, which tends to be forced deep into the fabric of cartridge filters where it can't be rinsed away, especially if the line velocities are too high for the system. It gets to the point that there's so much blockage that the filters lose their ability to pass water and trap debris. If the psi differential remains high after cleaning a cartridge, it most likely means the fabric has become clogged and the cartridge needs to be replaced.

Doing the Dirty Deed

Cleaning a cartridge is a matter of rinsing dirt from a somewhat difficult surface. The deep pleats of a cartridge, while increasing the filter surface area dramatically, are inherently hard to access. You have to get in there and get after it.

Plenty of service techs use a simple pistol grip sprayer on a garden hose — any device that can be turned on and off without going back to the spigot, will save water, which is important in drought-stricken areas. But a service tech looking to save time can use one of the products on the market specifically designed to force water down into the pleats and make this routine job go faster.

Millican is a fan of the Aqua Comb, a device that screws onto the end of the hose, with individual tines that put cleaning water in the right spot.

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"I just put the cartridge down on the ground, take a knee on my knee pad, get my Aqua Comb and go to town on the filter cartridge. I attack it at a 45-degree angle, get down to the band, take out the Aqua Comb, rotate the cartridge and go back in. All the dirt comes out the bottom — you go from a gray filter cartridge to off-white in two or three minutes. It's just plain faster than the garden nozzle, and as I said, I'm looking to save time. The problem with the garden nozzle is you're not focusing the water where it should be.

"If I pull up at my customer's pool, and they've got a hose hooked up near the filter, that's great, I'm good to go. I just screw on the device and clean the filter.

But if they don't have a hose hooked up, I keep a hose in my truck that already has the Aqua Comb attached, hook that up and I'm ready."

Of course, like sports teams, every tool has its fans. Perry Lusk of Perry's Pool Pump in Phoenix favors the Filter Flosser, which has a different design but achieves the same thing — rinsing water directed deep into many pleats at once, thereby shortening cleaning time and making it more productive and thorough.

"A lot of people bring in their cartridges to our pool store to be cleaned," he says. "We like the Filter Flosser because it's all metal, there's a quick-change piece that connects to your hose, and you've got an off/on ball valve so you can turn the water off at the Filter Flosser, so you don't have to go back to the tap.

"It's got machine cut holes that help you clean a bunch of pleats at once and it makes the job a lot faster and more efficient."

Saving Water

It's not exactly a tip, but any discussion of this topic has to include the fact that the water savings in cleaning cartridge filters is one of their major selling points in areas where water shortages are an issue, such as California, Arizona and Texas. That is to say, cleaning cartridges doesn't require the hundreds of gallons of wastewater needed to backwash a sand filter. Depending on the situation, a sand filter may run through 200 to 500 gallons of water in a single backwash cleaning. A cartridge might need five or 10. Saving that water is increasingly important.

Other Specialized Tools

There are specialized tools on the market that can speed cleaning up a bit. We already mentioned the Filter Flosser and the Aqua Comb, but another time saver is a specialized wrench that can quickly find purchase on the drain valve knob or the belly clamp nut and turn it. It just so happens that our friend Tal Millican has invented a couple of these products himself — one is called the Multi-Tork system, which consists of a set of socket heads designed specifically for the pool service technician.

"If you're taking off the cartridge filter clamp, for instance," he says, "you just pop one of the sockets on a cordless drill to take off the clamp in a fraction the time you'd need to do it with a socket wrench."

Millican also makes a tool called the Button-Hook — a precut wrench that fits on the most common filter drain plugs.

"Filter drain plugs are low on the case and they're often in hard-to-reach places," he says. "The Button-Hook is a specially bent-handled tool that allows you to access drain plugs in places that can be hard to get to with channel locks. That's what most people use — channel locks — but with channel locks you always have to keep an eye on it and if you don't grip the channel locks just right they don't work. With the Button Hook, once you get the drain plug in the slot, it can't move. All you have to do is turn it."

Winterizing Cartridge Filters — Making the Most of the Off-Season

At the end of the season, companies have a golden opportunity to use the down time to deep clean cartridge filters ahead of next season — and make some extra profit for the service. All Seasons does this as a matter of routine for all customers at the end of the season, using this step-by-step procedure as detailed by Lenz:

1. Hose off the filter
Using a standard garden hose, rinse off the filter from top to bottom. (We pre-treat with a little D.E. in our cartridge filters, which makes the dirt come off a lot easier.)

Never pressure-wash the filter, as the bands holding the pleats in place can snap under pressure. Should this happen, the pleats will collapse on themselves, reducing the surface area of filtration.

2. Soak the filter
After hosing down the cartridges it is important to put the filters through a soaking process. This can be done using 55-gallon plastic drums to allow the filters to soak overnight in muriatic acid and a filter-cleaning agent, which is available from most pool chemical manufacturers.

3. Repeat soak
Once the filters have soaked overnight, some pool technicians will lightly rinse the filters and place them in a fresh water drum to soak again. Once finished, an optional liquid chlorine bath can be performed to brighten and lighten the filters.

We do this final soaking so they look nicer when we return the filters to our clients. In some cases, these soaking procedures may need to be repeated depending on how dirty the filter cartridges are.

4. Air dry
Once the cartridge is clean, it is best to let the filter cartridges air-dry before using them again. Allowing them to dry completely gives the cartridge time for the fibers to fluff back up, which is important because the fibers need to expand to be effective. If not, they can be pushed down easily, which reduces the filter cycle.

We suggest the pool owner have two sets of cartridges. This allows the client to continue using their pool while the other set is being cleaned.

The service technicians that do the best work are those who take the filter media with them when they close the pool for the season, clean it at their shops, and return the filter ready to use in the spring when they reopen the client's pool. The process is important to also inspect to ensure that the filter media isn't ripped or torn. This is true not just of cartridge filters but also grid filters that can also have manifolds and o-rings that crack or need replacement. It's all a part of the winterizing/ cleaning of the filters.

This is beneficial in two ways, not only can the pool professional charge extra for the filter cleaning service, but they also have a customer with cleaner pool water all summer. This has become such a big service for us that it has kept one person busy, 40 hours a week between November and March every year. So much so that we can't get all the filters done. This year we plan to add another dedicated staff member to the filter cleaning process.

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We have an entire area in our warehouse that is set up in an "assembly-line" system. We actually bag the filter cartridges up in Hefty bags and deliver them back to the customers during the winter — and factor in the cost/price of the extra delivery. We prefer to deliver in the winter instead of delivering during the pool opening because the filters take up too much space in the trucks — space we need for other things.

It's a great stream of winter revenue for us. We charge about $120 per set of cartridges. With some customers having more than one set of filter cartridges — we are probably cleaning well over 1,000 sets of cartridges each winter.

Comments or thoughts on this article? Please e-mail scottw@aquamagazine.com.

Scott Webb is Executive Editor of AQUA Magazine.