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

Thread: sand filter question for newbie

  1. Back To Top    #1

    Join Date
    May 2013
    Location
    Benton, Arkansas
    Posts
    6

    sand filter question for newbie

    I bought a house with a swimming pool a couple of years ago. The pool was put in 2007. I decided to change the sand in the filter. (I know there is a debate about needing to change sand..) Anyways, I opened up the pool yesterday. I live in Arkansas so I should of opened (or not close it) earlier. I have tons of algae this year. It was the yucky kind that floats and in pieces.

    I was wondering about my sand filter. I noticed that when I was backwashing...the water wasn't that dirty. Today, I backwashed it a couple times, and the glass (on the filter) showed a little bit of dirty water more brown than green.
    Is this normal with new sand? Last year when I backwashed, it was always dirty green water.
    Is my filter working? It seems like I have to back was every 10-15 minutes due to pressure but the water isn't as dirt as I thought it would be.

    Today the water is blueish with some algae that I need to vaccum.

    TA 50 (I'm adding some backing soda today)
    ph 9
    CYA 20 (i need to add some)

    Thanks!
    21,250 gallons
    18 X 36 IG, Vinyl
    Sand 300 lbs. Hayward S244T
    Hayward Pump 1 HP
    Salt Generator Gold Line Controls

  2. Back To Top    #2
    Richard320's Avatar
    Join Date
    Jan 2010
    Location
    San Dimas, CA (LA County)
    Posts
    18,768

    Re: sand filter question for newbie

    Welcome!

    I can't help you much with the filter since I use DE myself and never close the pool. However, might I suggest stretching a knee-high nylon across your skimmer basket to strain out the biggest of the chunks?
    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!

  3. Back To Top    #3
    elwood58's Avatar
    Join Date
    May 2012
    Location
    Sun City West Arizona (2nd Home)
    Posts
    639

    Re: sand filter question for newbie

    You need to get that pH under control. Not sure how you got 9, but you need to get into the mid 7s. If your FC is over 10, it may be messing up your pH reading.
    19204 Gallon L Shape with a 10X10 2nd Step Baja Ledge. Intellichlor IC-40, IntellipH, Cartridge Filter, Pentair Heater/Chiller (Heat Pump). Tons of Deck with Deck Jets. Construction Complete 6/5/17.

    "If you don't measure it, you can't manage it!"

  4. Back To Top    #4

    Join Date
    May 2013
    Location
    Scottsdale, AZ
    Posts
    37

    Re: sand filter question for newbie

    I would have drained my pool if there were ever chunks floating in it. I can't imagine the time and headache to clear and balance that water.

    I wouldn't backwash so much. I've lived in my house for 9 years, and I've never changed the sand. I couldn't even speculate when ir if it was changed before then, but I'm going to say close to never. And I live in AZ, where we get those horribly sandstorms that make me run the filter for three straight days before I even get to cloudy blue.

    I'm lazy with backwashing, and I get to it maybe once a month. But, my pressure never seems to bounce over 19, so I leave it alone. When I do backwash, the water is definitely brownish, but it runs clear within 30 seconds.

    How high is your pressure getting that need to backwash so much? I'm in the camp of believing that sand needs to have some wear to work effectively, so I wouldn't be surprised that with your heavy filtration needs, it's not working optimally right now.
    12K play pool, sparkle quartz finish, Compupool salt system, PVC2000 infloor system, Emerson 3/4 filter motor, and AO Smith 1 HP infloor motor, PacFab Challenger Pumps

  5. Back To Top    #5
    Smykowski's Avatar
    Join Date
    Sep 2011
    Location
    Gurnee, IL (North Suburban Chi-town)
    Posts
    3,065

    Re: sand filter question for newbie

    First off, if you have visible algae, you need to shock your pool. See pool school for how to complete the process.

    As for the backwashing, how often are you backwashing, and what is causing you to backwash? We recommend backwashing when you pressure rises 25% above clean pressure. In a dirty pool during the shock process, backwashing might be required as often as daily. In a clean pool, backwashing shouldnt't be required more than once every couple of weeks. I think I backwashed every 6 weeks or so last summer.
    33' round, 23,000 gal AG vinyl , 1HP 2spd PowerFlo Matrix downsized with 3/4HP impeller (X2), Hayward S180T 150# sand filter (X2), Hayward H250 NG heater Pool Store year 1 - $850 for 2 months; Pool Store year 2 - $440 for 2 months, TFPC year 1 - $170 for 4 months; TFPC year 2 - $95 for 4.5 months
    The most important article on this site - The ABCs of Pool Water Chemistry

  6. Back To Top    #6

    Join Date
    May 2013
    Location
    Benton, Arkansas
    Posts
    6

    Re: sand filter question for newbie

    When my filter runs it's about 10psi...I have been backwashing when it gets to 20 psi. I have never had to backwash this many of times this year. I can not leave my filter on during the night because I"m afraid the psi would get to high and it might ruin my pump.

    I am going to vaccuum the chuncks of algae tomorrow.

    When I first opened it...I could only run the filter about 10 minutes...Now I can run it about 45 minutes. I wished I never changed the sand. I know my laterals are fine. Is there another reason whey my filter is not running normal? Or can a real dirty water make it hard on the filter?

    My water is bluish with some dead algae at the bottom. The water is real cloudy and it looks oily on top.

    My ph is 9...if I shock my pool with beach...I thought that would make my PH jump ever further up?

    I was thinking that the new sand might take awhile to start working properly.
    21,250 gallons
    18 X 36 IG, Vinyl
    Sand 300 lbs. Hayward S244T
    Hayward Pump 1 HP
    Salt Generator Gold Line Controls

  7. Back To Top    #7
    Richard320's Avatar
    Join Date
    Jan 2010
    Location
    San Dimas, CA (LA County)
    Posts
    18,768

    Re: sand filter question for newbie

    You need to adjust the pH with acid. Bleach is alkaline, but once it breaks down, the net effect is inconsequential.

    Filters are designed to catch stuff. So if there's a lot of sludge, it will load up fast.

    Chunks of algae and oily film don't sound good. See if you can't pull some of that stuff out with a leaf net or skimmer. It will reduce the bleach consumption.
    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!

  8. Back To Top    #8

    Join Date
    May 2013
    Location
    Scottsdale, AZ
    Posts
    37

    Re: sand filter question for newbie

    Why won't you drain and do a fresh fill? Your water issues sound so extreme.

    And yes, your filter is working double time, but I suspect that has less to do with your new sand, and more to do with what's in the water (ie. "chunks").
    12K play pool, sparkle quartz finish, Compupool salt system, PVC2000 infloor system, Emerson 3/4 filter motor, and AO Smith 1 HP infloor motor, PacFab Challenger Pumps

  9. Back To Top    #9

    In the Industry

    duraleigh's Avatar
    Join Date
    Apr 2007
    Location
    Sebring, Florida
    Posts
    30,084

    Re: sand filter question for newbie

    If your clean filter pressure is 10 psi, I would backwash as soon as psi approaches 12 - 13 psi.

    Even if the psi goes way up, it will have NO affect on your pump

    Not sure how you are testing pH at (most tests don't go that high ) but it is IMPORTANT to have your pH in the mid 7's

    Is there another reason whey my filter is not running normal?
    Sounds to me like it is operating just fine. Filters are in your circulatory system to catch debris.....that's their only purpose and yours is catching a lot of debris.

    Chlorine has NO effect on pH.

    Changing the sand is virtually never necessary but done is done.

    You are operating under several misconceptions....chlorine is an absolute necessity for clearing algae in your pool and filtering out the dead algae is a necessity for getting it out. You cannot vacuum or filter out algae until you kill it with chlorine.



    read "The ABC's of Pool Water Chemistry" up in Pool School, then read "How to Shock Your Pool".
    Dave S.
    42k vinyl and concrete pool, 1.5hp pump, 140gpm filter
    TFTestkits , PoolMath , Pool School

Posting Permissions

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