Become a TFP Supporter Pool Math Forum Rules Pool School
Results 1 to 9 of 9

Thread: clogged cartridge filter?

  1. Back To Top    #1

    Join Date
    Jun 2014
    Location
    Alexandria Virginia
    Posts
    18

    clogged cartridge filter?

    My pool is permanently cloudy.

    The chemistry measures normal.

    Pentair Clean and Clear filter. 10 micron cartridge filters.

    Yesterday, because the pressure in the filter had increased by 10 pounds, I pulled the cartridges and hosed them.

    Two hours later, the pressure had again increased by 10 pounds.

    Is it possible that, after less than one full season of use, these filters are hopelessly clogged and need replacement?

  2. Back To Top    #2
    Mod Squad JohnT's Avatar
    Join Date
    Apr 2007
    Location
    SW Indiana
    Posts
    9,086

    Re: clogged cartridge filter?

    Welcome to TFP!

    It may be possible, depending on your water chemistry and what's been used in the pool.

    The more likely possibility is that you have algae in the water causing cloudiness and the filter is getting clogged trying to clear it. The chemistry guidelines you hear from pool stores or see on pool chemical packages are next to useless. The parameters affect each other, so a level that is crazy high chlorine in one pool could be crazy low in another pool.

    To help you out, we need to know your water chemistry numbers: Free Chlorine, CYA and Hardness for starters.
    TFP Moderator
    20K Gallon 20X36 Vinyl Inground
    Hayward S244T Sand Filter with 1HP Whisperflo Pump. Liquidator C-201 and Solar Heat

  3. Back To Top    #3
    JasonLion's Avatar
    Join Date
    May 2007
    Location
    Silver Spring, MD
    Posts
    37,879

    Re: clogged cartridge filter?

    The pressure going up rapidly means the filter is doing it's job correctly. The water is cloudy and the filter is filtering out whatever is causing the cloudiness. Everything here suggests that the filter is working very very well and just need to cleansed regularly until it finished getting the cloudiness out of the water. Of course, you also need to make sure the chemistry is appropriate, kill any algae, etc.

    If the filter was failing, it would have a high starting pressure right after you cleaned it.
    19K gal, vinyl, 1/2 HP WhisperFlo pump, 200 sqft cartridge filter, AutoPilot Digital SWG, Dolphin Dynamic cleaning robot
    Creator of PoolMath and Pool Calculator. Other handy links: Support this site, TF Test Kits, Pool School

  4. Back To Top    #4
    Richard320's Avatar
    Join Date
    Jan 2010
    Location
    San Dimas, CA (LA County)
    Posts
    18,768

    Re: clogged cartridge filter?

    Let's look at it logically. The pool is cloudy. Stop. That indicates a chemistry problem of some sort.

    Now, it could just be dead bleached algae carcasses, and the filter should strain them out, and apparently it is: "Two hours later, the pressure had again increased by 10 pounds." A really cloudy pool can load up a good filter in a startlingly brief time. And if the chemistry is off, more and more algae is being grown and killed off creating a never-ending supply to clog the filter.

    "
    The chemistry measures normal." Normal may not be correct. A man 5'6" tall may weigh 300 lbs. That is his normal weight. Just because it holds steady at 300, doesn't mean that it is healthy. "Normal" is subjective. We need objective numbers; test results. And it also helps to know just how those results were obtained - pool store, test strips, 2-way test kit from Walmart, TF100....

    Have you added anything special? Certain algaecides will combine in a nasty way with Cal-hypo "shock" if they were added too close together. If the pool store sold you phosphate remover, it can easily turn your pool to milk.
    16K freeform gunite with spa; Pentair 4000 DE filter; Century Whisperflow 1 HP; Pentair Minimax heater.
    Troublefree does not mean Maintenancefree. It's like brushing your teeth: You can spend a couple minutes a day and pennies a week or go to the dentist once a year and spend several thousand dollars.
    A pool is like a pet - you have to feed it every day, even the days you don't want to play with it!

  5. Back To Top    #5

    Join Date
    Jun 2014
    Location
    Alexandria Virginia
    Posts
    18

    Re: clogged cartridge filter?

    Where to begin......
    Here are the numbers as of a few minutes ago.
    Free Cl: > 5
    pH: 7.5
    hardness: 200
    CYA: 40
    Results obtained with a Taylor kit.

    Yes, I have added both an algaecide and a "clarifier" last week. In desperation.

  6. Back To Top    #6

    Join Date
    Jun 2014
    Location
    Alexandria Virginia
    Posts
    18

    Re: clogged cartridge filter?

    Because the pool was cloudy for the first three years that we have lived in this house, last year I replaced the existing sand filter with a cartridge filter. My rationale was that the debris in the water was too fine for the sand to trap it.

    I should mention that the pool is embedded in a wooded lot. Even in mid June, the leaf cover is so complete that the pool is in direct sunlight on only 1/3 of its area and for only several hours of the day.

    There is no doubt that pollen and such from these trees is contributing to the cloudiness. This is evident on the water surface.

    Did I make a mistake trying to filter this to a 10 micron level instead of just trapping larger particulates in sand?

    Otherwise, I see myself cleaning filters several times a day.

    Not at this stage of my life!

  7. Back To Top    #7
    JasonLion's Avatar
    Join Date
    May 2007
    Location
    Silver Spring, MD
    Posts
    37,879

    Re: clogged cartridge filter?

    A properly cared for pool can be kept crystal clear regardless of the kind of filter. A cartridge filter can clear things up more quickly, but doesn't make a fundamental difference in clear or not clear water. It is proper water chemistry that determines if the water is clear or cloudy. Get your chemistry too far off, or get algae, and no filter can keep the water clear. The filter only needs to be cleaned frequently because some is wrong, as shown by the cloudy water. Once the water is cleared up the filter will go far far longer between cleanings.

    Pollen does tend to collect on the surface of the water, and will eventually sink to the bottom and pile up as visible dirt/dust there. But it does not cause the water to get cloudy.

    Do you know your TA level?

    I strongly recommend getting a test kit that can measure FC levels above 5. To properly kill algae you need to raise FC up to around 16 and maintain it there. There isn't any practical way to do that with a test kit that only reads up to 5. The FAS-DPD chlorine test is the one to get.
    19K gal, vinyl, 1/2 HP WhisperFlo pump, 200 sqft cartridge filter, AutoPilot Digital SWG, Dolphin Dynamic cleaning robot
    Creator of PoolMath and Pool Calculator. Other handy links: Support this site, TF Test Kits, Pool School

  8. Back To Top    #8
    Richard320's Avatar
    Join Date
    Jan 2010
    Location
    San Dimas, CA (LA County)
    Posts
    18,768

    Re: clogged cartridge filter?

    Now we're getting somewhere!

    >5 FC could mean 6 or it could mean 20. To kill algae faster than it is reproducing requires shock level, which is 16 FC for 40 CYA. You can't measure that high with your test kit. The good news is, you don't need to buy a whole new test kit. You can just add the FAS-DPD tester, which can measure FC up to 50. You can get it here: http://tftestkits.net/TF-100-Test-Kit-p47.html And no, I get no commission.

    Millions of people successfully use cartridge filters. No filter can keep up with the load placed on it by an algae bloom. Since you added algaecide, I think we can assume that it was green not so long ago?

    What you need is to get ahead of the algae growth by performing the Shock Level and Maintain Process. It will use an alarming amount of bleach or liquid pool chlorine initially, and it may take a few days after the algae is all dead to clear up, but it works.

    You'll be cleaning that filter a bunch during the process, but take solace knowing this may be the last time you ever need to go through the Shock Level and Maintain Process. Once you get rid of the algae, your water will clear up and sparkle and you'll be cleaning the filter at normal intervals. On that note: you can stop a whole lot of pollen and floating debris from clogging the filter by using a skimmer sock: http://www.troublefreepool.com/threa...on-Illustrated
    16K freeform gunite with spa; Pentair 4000 DE filter; Century Whisperflow 1 HP; Pentair Minimax heater.
    Troublefree does not mean Maintenancefree. It's like brushing your teeth: You can spend a couple minutes a day and pennies a week or go to the dentist once a year and spend several thousand dollars.
    A pool is like a pet - you have to feed it every day, even the days you don't want to play with it!

  9. Back To Top    #9

    Join Date
    Jun 2014
    Location
    Alexandria Virginia
    Posts
    18

    Re: clogged cartridge filter?

    You know, I just joined this forum because I was at my wits end with the pool that we inherited from the previous owner of the house. The company that opens and closes our pool is helpful but not with details.

    I belong to any number of other forums - vintage VW, hobby machinists, etc.

    Based on the quantity and especially the information content of the replies to my posts, this forum might turn out to be the best yet.

    Many thanks.

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •