Filter Fixation

Aq 704 79pg 0001

Late on a Friday morning you get the following voice message from a worried client: "I think there's D.E. in the bottom of my pool and I don't know what to do. I've got a huge birthday party tomorrow for my 10-yearold son and the pool simply must be open for the kids. Do I need a new filter? What's going on? Can you help me?" Service techs know there may be a tear in one of the D.E. filter grids and it simply needs to be fixed. Here's the real question: Is this a repair you want to tackle on Friday afternoon? Probably not, since the most appropriate repair of torn grids would require you to tear down the filter and hike out to the supply house for new ones, and by that time it could be 5 p.m. So what should you do? First, return the client's call — no customer likes to be ignored. Then explain the options and let the client decide whether she wants the filter temporarily patched or properly repaired.

In this client's case, the filter problem required a repair, but this scenario leads to a more general question: Which filter problems call for a fix and which ones call for a totally new filter? AQUA spoke with a few industry experts and asked them that question. As experienced service technicians may already know, many problems just call for a fix, but there are also situations where a new filter is necessary or desirable.


Here's the good news for service companies: Most filter problems can be fixed and wise homeowners hire you, the professional, to do the job. The bad news: some fixes are easier said than done. For instance, in the scenario above, changing out D.E. grids may sound simple, but the process is quite messy and time consuming. "We have a general rule of thumb," says Bob Fowler, president of Fowler's Pool Service & Supply in Lemon Grove, Calif., "that we do not tear down any filters on Friday because we know we may not be able to get back until Monday and we don't want to leave the systems down over the weekend. So unless it's an emergency, we work on the filters Monday through Thursday." Fowler acknowledges that you can temporarily patch a D.E. grid with PVC glue or duct tape, but he'd rather not resort to these less-than-ideal quick fixes.

Before assuming the bypassed D.E. or debris is being caused by a torn grid, Fowler says he always first checks to make sure the O-ring on the backwash valve is not creating the problem. "When we know we've got a repair starting with a filter that's bypassing debris, before we break the filter apart, the first thing we do is take the backwash out and see if the O-rings are intact."

However, if the D.E. grid is torn, techs will want to investigate the cause of the tear. If it's just normal wear and tear, replacing the grid should do the trick, but if the grid tore because the pump is too big for the filter, simply replacing the grid is not going to solve the root problem. If the pump is too big, there are a couple of options. "You can put on a smaller pump, but this may not require a totally new pump," says Tom Larson, senior product manager for Sta-Rite Industries. "You may just be able to change out the motor and impeller because most series of pumps have the same componentry with the exception of the motor, impeller and diffuser. So that way you just have to change the motor half, and you don't have to mess with any of the plumbing."

The other option is selling the homeowner a bigger filter (assuming the rest of the equipment and plumbing can handle the larger pump as well). Says Larson, "We've got conversion kits, a lot of the filters do now, and that's what we're gearing everything towards: Have the same tank for different media and different sizes so you can just change out the internals and upgrade the size that way."

An oversized pump can also result in channeling in a filter sand bed and cracked laterals, so the pump/filter relationship is something to check if either of these problems crop up. However, both of these problems have other causes, as well. Improperly maintained water chemistry can also lead to channeling and cracked laterals, so simply replacing the sand may only temporarily remedy the problem. "If you're not chemically treating your water properly and your sand bed gets hard, it can calcify, it can get like concrete, but the water will still want to go through it," says Larson. "And since water is going to take the path of least resistance, that can start channeling. The first sign of that is that you're not getting good filtration, your water is getting dirty. So more times than not, you're catching that before the chemicals attack and damage the plastic laterals because the homeowner notices the filter is not filtering and cleaning as it should."

Even properly maintained sand needs to be changed from time to time. Tom Donaldson, executive director of the Aquatic Training Institute in Gainesville, Fla., advises pool owners to have their sand replaced every two to three years.

"Some people contend that sand lasts forever if you keep it properly chemically cleaned. I just feel that sand ought to be replaced every couple of years," says Donaldson. "But of course I'm in Florida, so we run our pools a bit more than they do up north."

Donaldson also recommends replacing cartridges regularly. "Everybody should have two sets of [cartridges] and they should get about 2- years out of two sets if they interchange them and chemically clean them."

The condition of the cartridge may also indicate that it needs to be replaced. "If I grab at one of the cartridge pleats and I get a lot of fibers off in my hand, I replace that cartridge because it's falling apart," says Donaldson. "Once the media starts coming off, it's time to replace."

D.E., of course, needs to be replenished after each backwashing and the general rule of thumb for the amount of D.E. required is 1 pound of D.E. per 10 square feet of filter area. It's critical to add enough D.E. "because if you don't put enough D.E. into cake the grids, then you can get oils and debris on the grid," says Larson. "Because the grid is a woven material, something can get in between those weaves, and once it's in there, if it doesn't go all the way through, it's stuck."

Unfortunately, pinpointing the exact grid to fix can be difficult. "It's hard to tell with the naked eye which grid it is, so I'm sure many times techs just replace the whole assembly. You can try soaking them in a solution that might break up some of that stuff and you can do that with the entire grid assembly also. With StaRite's new grid assembly, the advantage is that it's not woven, it's a different material, it's more like a cartridge filter. So since it's not woven, you're not going to get the dirt and debris embedded in there."

Drip, Drip

Replacing filter media often enough will definitely help to prevent various snafus, but problems can still arise. Most every tech has serviced a leaky filter and oftentimes the culprit is pinched, worn or cracked O-rings or O-rings that may have taken a seat. The fix for this situation is simple: replace the O-ring(s). But how often this should be done and which O-rings to use are decisions each tech must make.

"We have a program within our company," says Fowler, "where every year for our existing customers — and we do strictly residential pools — we take their filters apart and clean them. Replacing the O-rings is just like an oil change — you just do it, you don't even think about it.

"And we prefer the OEM's O-rings and we actually go out of our way to find them. They usually cost a lot more, but they work. The problem is if you use a generic O-ring and it leaks, you'll get a callback the following week about how the filter is still dripping, and then you've lost all the profit in that job by having that generic O-ring in there."

Fowler's decision to use OEM Orings makes sense, especially when you compare the situation to cars: Would you put a Ford part on a Toyota truck. A good mechanic wouldn't. That said, a generic O-ring could work as long it's compatible, but that's the tricky part. "There are credible companies that make replacement O-rings," says Steve Gutai, product manager for pumps, filters and valves at Jandy. "But I think what happens a lot of times is there are so many different O-rings from so many different manufacturers that they don't always get the right O-ring. I think that's probably more what the problem is versus the part. And I think the reason some service guys like to use the OEM O-rings is because they know they're going to get the right part."

Besides leaks, a couple other problems that require relatively simple fixes include a clogged screen in the air relief valve or a pressure gauge that reports irregular readings (most run somewhere between 4 and 20 psi) or shoots up overnight even though the filter is clean. In each case, once you know the cause of the problem (a pressure gauge shooting up could be caused by a malfunctioning air relief valve), you simply replace the faulty part.

Another relatively simple repair that some don't do often enough is replacing the band clamps. "We recommend in our manual changing the band clamps every five years," says Larson, "because you want those in good operating condition."

Donaldson agrees clamps should be changed often enough, but his criteria is different: "I replace them when they're difficult to take off or put on. That's one of the things I think people don't replace as often as they should. Then they go through the frustration of having to deal with them. When they're difficult to work with, when they're not working right, just get new ones."

Bad clamps can lead to other problems, as well. "Some of the older pressure systems have such a difficult clamping and opening and closing mechanism on them that it really discourages the customer from taking care of and cleaning the filter," says Donaldson. "So in those cases, from a customer-convenience standpoint, if they've gotten 10 years out of that filter, it's paid for, it doesn't owe them anything and it's time to move them up to something they're going to be happier with."

Bigger, Better, Newer

Upgrading a filter is a fairly common reason to replace one, especially if the unit has been around for a while. "Some of the new models the manufacturers are putting out are a heck of a lot easier to use and require a lot less maintenance," says Donaldson. "And it's not a bad thing if you say to a customer who's got an old filter, 'Look, it's time to get something new and we've got these new filters that you only need to clean once or twice a year, so you might want to consider that.' And that's a revenue source for techs, too."

Besides allowing for more time between cleanings, some newer filters offer other conveniences as well. Says Gutai, "Pool equipment is getting to the point now where it's much more efficient, it's easier for the consumer to operate and the equipment quite frankly is more durable than it used to be."

Gutai points to the durable plastic housing now used on most filters, and to other innovations that have made filters easier to use. "Filters are all going much more toward an ergonomic theme. We've designed our filter line to have handles on the lid, so when a consumer or tech takes the filter lid off, they have something to grab onto. Just five years ago, no one had handles on their lids.

"We also have a special type of pressure gauge that has a .oating collar that allows a customer to look at the pressure reading on the gauge without having to mark it up. In the past people had to use marking pens."

Of course getting a better, more modern filter isn't the only reason to replace a filter. "With filters that are pressure vessels, the thing you look for is certainly any .aw or crack in the casing that doesn't allow it to hold pressure anymore," says Donaldson. "Because if you have a crack in the body of a pressure vessel, it can blow up or the water can escape and it'll start leaking. So in that case you probably need to replace the whole filter.

"And if you're going to replace either half of the pressure vessel, you [should] replace the whole vessel. That's what I would recommend. Because, quite frankly, the same conditions that caused the problem with the bottom of the tank also exist with the top of the tank. So if you had some chemical problems or whatever, you're probably going to have a problem with the other half of the tank, so just go ahead and replace it all at the same time."

Fowler agrees: "If it has any age on it at all — and that's probably three years plus — you just replace the whole filter because the plastics expand and contract differently and they don't match up that well is what we've found."

If you come across pinholes in a stainless-steel filter tank, that's another reason to replace the whole unit. "That's the death toll for that tank, it's gonna get replaced," says Fowler. "Lots of times what a pool guy will do is he'll try to save the customer a few bucks by patching this, instead of doing a replacement. And in the long haul, it ends up costing him more time and money because he should've replaced it in the first place."

Sometimes a problem that could be fixed may be so costly that the pool owner may be better off getting a whole new filter. "If you open up a 15year-old filter and all the grids inside are shot, are you doing the customer a favor by just replacing the grids when you figure out all the labor involved and the parts?" asks Fowler. "I think the service to the customer is when you give them the option. You say, 'This is what it's going to cost to repair this and this is what a new filter costs. Which would you prefer?'"

Or perhaps you've come across an older filter with numerous small repairs that need fixing. This is also a good time to consider replacing the whole unit. Even when a filter is properly maintained, Larson says, it's no different than a car — after a while, it comes time to say goodbye.

Content Library
Dig through our best stories from the magazine, all sorted by category for easy surfing.
Read More
Content Library
Buyer's Guide
Find manufacturers and suppliers in the most extensive searchable database in the industry.
Learn More
Buyer's Guide