After 7 years, I've replaced my 4 cartridges in my filter (I could have gone longer, but the straps were starting to break and I figured I had a good run with these cartridges). The replacement cartridges for my Jandy CL340 were from Unicel^® and they had instructions with them that I thought were helpful and consistent with what we've been telling people -- note the specific instructions for Baquacil/Biguande as well.

Cartridge Cleaning Instructions for Chlorine Users

When should a cartridge element be cleaned?

For swimming pools, clean the cartridge when filter canister pressure reaches 8 PSI above the initial system or new cartridge starting pressure. For spas, establish a routine cartridge cleaning schedule based on the amount of spa usage. If Baquacil^® is used as a sanitizer, the filter element must be cleaned with Baqua Clean^® before any cartridge cleaner is used (Step 4). Please refer to "Cartridge Cleaning Supplement for Baquacil^® Users."

What is the procedure to clean my cartridge?

1. Remove the cartridge from the filter housing following the manufacturer's instructions.
2. Use a garden hose with a straight flow nozzle to wash down the filter element. Work from the top down, holding the nozzle at a 45 degree angle, and wash all the pleats with emphasis between pleats.
3. Rinse until all dirt and debris are gone.
4. For all spa cartridges and elements used in swimming pools where perspiration, suntan lotions, and other oils are present, soak the element for at least on hour (overnight is most effective) in (1) a commercial filter cleaner; or (2) one cup trisodium phosphate (TSP) to five gallons water; or (3) one cup dishwasher detergent to five gallons of water.
5. Rinse the cartridge again to remove oils and cleaning solution.
6. If the filter has a coating of alage, calcium carbonate (residue from calcium hypochlorite), iron, or other minerals, soak the cartridge in a solution of one part muriatic acid to twenty parts water until all bubbling stops. WARNING: Failure to remove all oils and cleaning solution before acid soaking will result in a permanent restriction of water flow and cause premature cartridge failure.
7. Rinse the cartridge clean and reassemble housing.

NOTE: Unicel does not recommend the use of diatomaceous earth (DE) with cartridge filters. DE particles will become trapped in the body of the media and shorten cartridge life. If desired, a cellulose fiber (synthetic DE) can be used in moderation.

Cartridge Cleaning Supplement for Biguanide Users

What should I know about cleaning my cartridge element if I use a biguanide system such as Leisure time Free^TM or Baquacil^®?

Unlike chlorine which oxidizes the bacteria in the water, the active ingredient in biguanide systems, polyhexamethylene biguanide (PHMB), destroys the bacterial cells. PHMB locates and binds to the bacterial surfaces, and then attacks the outer bacterial wall. Once this wall has been compromised, the inner cell membrane (the cytoplasmic membrane) is destroyed. This destruction allows the cell contents to disperse into their surroundings where they are further broken down into their elemental parts by a non-chlorine oxidizer such as Leisure Time Boost^TM or Baqua Shock^®.

In addition, Leisure Time Boost^TM and Baqua Shock^® are mild coagulants which combine bacterial cells and other small particles in the environment into particles large enough to be trapped by the filter. The resulting deposit is a gray sticky film on the media which can only be removed with Leisure Time Filter Clean^TM or Baqua Clean^®. If trisodium phosphate (TSP) or any TSP type cleaner is used prior to stripping the film, the cleaner and the gray film will combine to form a gum-like substance. Once this occurs, the substance cannot be removed from the media and the filter cartridge must be replaced.

WARNING: Follow all manufacturer's instructions, warnings and cautions when using Leisure Time Free^TM or Baquacil^® products.

Leisure Time^® and Leisure Time Free^TM are registered trademarks of Advantis Technologies, Inc.

It's going on 4 years for my "monster" and I've started to see a few of the bands break as well. The filters are in pretty good shape so I spot hot glued the bands back together and they seem to be holding together fairly well between cleanings.

Also, I would like to point out that cleaning cycles of longer than 3 months are possible with the proper sizing of the filter. I've been cleaning my filters every 6 months (no closing) and it seems to be working out fairly well. The filter shows less than a 1 PSI rise by then but then again, we don't have a very dirty yard. Fall and winter are the worst for us so I usually clean in spring and early fall. I really don't see the need or have the desire to clean more often than that.

Also, I understand why manufactures recommend an 8 PSI rise before cleaning a filter so as to minimize the frequency of cleaning but keep in mind that 8 PSI results in over 15 feet of additional head loss in the plumbing and will probably have a big impact on flow rates.

This is another good reason why I think it is a good idea to oversize the filter. The cleaning cycle is measured in months instead of weeks and there is no need to wait until 8 PSI before cleaning. I'm pretty happy with a large filter.

I totally agree. I clean my monster cart just once a year at the start of the season. I barely see a 1 PSI rise. The filters are nevertheless dirty, mostly with what appears to be suntan lotion and cedar needles.

I must say that buying the new cartridges was a lot easier than cleaning the old ones, but 4 new cartrdiges cost a pretty penny (around $340). Maybe next time I'll glue the bands and maybe be able to go 10 years.

Great post Waterbear

Is it possible for you to post a picture of the 4$ garden hose nozzle?

This is the kind that I use... not this one exactly, but very similar... just a simple non-adjustable nozzle that makes a perfect stream.

Thanks Eskimo!
I will look out for something similar here.

//Mats

And that picture is exactly the type nozzle I am talking about. You want a small bore nozzle (the hole the water comes out), which is usually the short one (it comes in long and short).

I have been using this cartridge cleaning method for about a year now, with great success. I have the exact brass hose fitting in the picture. I soak in TSP every cleaning. I have two cartridges. The only thing I would add is to buy a little yellow fitting for the hose which is an on/off switch. The yellow fitting goes on first, then the brass piece. This makes it much easier for me to turn on and off then going back and forth to the spigot. I also enjoy it more in the summer than winter -- you get kinda wet from splashback.

we picked up that brass nozzle at Lowe's a couple of weeks ago (i only just saw this post tonight!)

but we picked that one up because we noticed that it screws onto the end of the regular, plain old fashioned solid metal spray thingie for the hose. so instead of having a plastic valve, there's the metal sprayer with the flip-tab that holds the spray into the on position. and the brass nozzle unscrews for the rare occasion we need to use the hose for something other than rinsing out the cartridge.

I am posting to recommend the purchase of the small, fixed brass nozzle shown a few posts earlier. If you have a filter cartridge BUY ONE NOW. I read this post a while back but figured using my existing hose nozzle would be fine. This season I have had problems with too much pressure in my 4 cartridge, 320 sq/ft filter. The pressure has been 8-9 PSI higher than last season since I opened the pool in May. I have cleaned the filters "thoroughly" twice so far trying to reduce the pressure. Today I bought the brass nozzle shown and cleaned my filters again today with it. What a difference! The nozzle really cleans the funk out of the pleats. I reassembled everything and my pressure is now back to where it was when the filters were new (20PSI).

Hello All,

I have a PentAir 420 filter, which uses 4 105 square foot cartridges. The cartridges are each 26 inches long. I have obtained a new plastic 35 gallon trash can that the 4 cartridges will just barely fit in with only the very tops above the water when the can is filled to the brim.

I have the brass nozzle and several 1 lb boxes of Savogran TSP. I have verified by measuring that a 1 lb box of TSP is 2.5 cups, and have read the recommendation to use 1 cup per 5 gallons of water. Assuming that my 35 gallon trash can holds 35 gallons of water (I didn't verify this), that means I need to use 7 cups, or approximately 3 lbs of TSP.

I have also obtained 4 new filter cartridges, and intend to install them while I clean the current ones. It's currently below freezing at night here in Texas, and I don't want to leave the pool off overnight while I soak the current cartridges.

Here are my questions:

Have I done the calcs right and is 3 lbs of TSP the right amount?
Is there a different procedure for installing new, dry filters and starting up the pool?
How should I store the current filters once they are clean?

Thanks a ton. This site is a great resource.

--Chip

Although the can holds 35 gallons, it'll probably only hold a lot less with all 4 cartridges in it. So 7 cups would be too much. You'll have to see how much water it takes to fill the can with the cartridges in it. My guess is half that?

First, find the amount of displaced water when adding a cartridge.

Fill a vessel such as a clean garbage can with enough water to cover a cartridge. Measure the volume.
Mark the water level.
Add a cartridge. Agitate it to knock off and trapped air.
The water level will have risen some. Siphon off the water into a large corn pot until you get the water level back to the original mark.
Measure the amount of water in the corn pot. That is how much water is displaced by a single cartridge. Adding additional cartridges should displace the same amount.

Now you can calculate how many gallons and how much TSP.

Scott

Thanks for the tips on how to determine how much TSP to use.

Anyone know if there are special startup procedures when installing new, dry cartridges?

Also, is there anything I should know about long term storage of cartridge filters?

Thanks again,

--Chip

Hi Chip - not sure why this post was not answered more timely.
When I get a new cart I just put it in the filter and I'm good to go.
I make sure to clean the filter as instructed above; and then I make sure it's completely dry before I store it in the shed, I leave it uncovered.

Thanks again!

I'm thinking that instead of the trash can soaking my filters in the cartridge unit itself. I figure I can put rags in the inlet/outlet pipes, unscrew the covering on top where the pressure gauge is and fill it up to soak. I'm sure a small amount of TSP would still seep into the pipes and find its way into the pool.. is that an issue?

I know its against the "rules" of cartridge cleaning, but, for years I have used a pressure washer without any damage to the elements. JMHO.

I wouldn't recommend that....

Any ideas on life expectancy of filter elements. I have the Starite system 3 with the large one and smaller one. Mine are going on 4 years.