Become a TFP Supporter Pool Math Forum Rules Pool School
Results 1 to 8 of 8

Thread: Sand filter maintenance problem

  1. Back To Top    #1

    Join Date
    Aug 2010
    Location
    la Ceiba, Honduras
    Posts
    3

    Sand filter maintenance problem

    I got my pool out of balance and had an algae problem. Basically a heavy bather load was not properly taken into account. The FC was raised to 30 ppm with HTH, the CYA was around 70, Alkalinity was low due to rain corrected with sodium bicarbonate to 100 ppm. Calcium level is 260 ppm
    Got a huge milky water problem that yielded a white back wash flow. I am guessing that this is the dead algae
    The cloudiness would not filter quickly. Opened the filter a TR 140 Pentair and found a lot of hairy scum in the sand around the sides, clearer towards the middle. Filter in service for about 5 years, backwashed only.
    I am removing the good sand and washing it and reusing, in addition using 200 lbs of new sand for final fill in top of filter.
    Sand in Honduras where we are located is close to $20 per bag as it is all imported. (900 lbs needed for full refill)
    When refilling with water before backwashing, will add filter cleaner and allow to sit for a day.
    I have a 45 foot negative edge on this pool and no skimmer so don't have a way to add the filter cleaner during a back wash.
    Question, Is it better to use pebbles beneath the laterals?
    Any ideas on procedure would be appreciated.
    Thanks Richard
    45,000 gallon reinforced concrete, Hydrazzo lined infinity pool. Pentaire 11 sand filter, 3 hp Intelliflo and 3 hp Hayward recirculation pump. 3 Fiberstar Laminar fountains, Nexxus savi Lights. Zodiac Duoclear Chlorine generator.

  2. Back To Top    #2

    Join Date
    Aug 2010
    Location
    la Ceiba, Honduras
    Posts
    3

    Re: Sand filter maintenance problem

    One other point. The filter was full of dirty water all the way through. The initial water color from the drain was brown. That is blown dust and above that grey. I believe that I was never backwashing this filter enough. Basically I wo=uld watch the outflow and as soon as it became clearer I rinsed and filtered. That maybe a minute or so. In future I will backwash for at least 3 to 5 minutes. Quite a bit of water at 160 gpm but i have plenty of water in my stream so costs only chemicals.
    One other point salt is 15 bucks a bag here too and it rains a lot. The pool is now a chlorine based sanitation system using external sources depending on various levels CYA CA etc. Bleach is expensive here too so mostly Dichlor or hth type calcium Chloride.
    Richard
    45,000 gallon reinforced concrete, Hydrazzo lined infinity pool. Pentaire 11 sand filter, 3 hp Intelliflo and 3 hp Hayward recirculation pump. 3 Fiberstar Laminar fountains, Nexxus savi Lights. Zodiac Duoclear Chlorine generator.

  3. Back To Top    #3
    Mod Squad Bama Rambler's Avatar
    Join Date
    Jun 2009
    Location
    SouthWest Alabama
    Posts
    22,347

    Re: Sand filter maintenance problem

    I agree that you weren't backwashing long enough.
    Since it rains a lot I think you can manage the CYA and CH levels by careful planning. Take a look at some of Richard320's posts to see a good example of water planning. He had high CYA and CH but has managed to bring it down using roof runoff and planning.
    Dave J. TFP Moderator
    24' x 52" Round AGP. 2hp/¼hp SPL Power-Flo 2-speed pump. 200sqft Waterway Cartridge Filter. 45MHP2(3GPD) Stenner Peristaltic Pump
    Pool School ----- Pool Math ----- TF-Test Kit

  4. Back To Top    #4

    In the Industry

    duraleigh's Avatar
    Join Date
    Apr 2007
    Location
    Sebring, Florida
    Posts
    30,083

    Re: Sand filter maintenance problem

    I have that same big filter and it runs troublefree. HOWEVER, in addition to some pretty good backwashes during the season, each spring I open it up and redistribute the sand and clean it out with a hose and sifter. I didn't do that the first four years and I had quite a mess so I learned my lesson.

    Mine takes only about 30 minutes to clean it really thorough and about the same amount of time to open it up and button it back down....1 hour total.
    Dave S.
    42k vinyl and concrete pool, 1.5hp pump, 140gpm filter
    TFTestkits , PoolMath , Pool School

  5. Back To Top    #5
    Puffin's Avatar
    Join Date
    Jul 2010
    Location
    Metro Atlanta, Georgia
    Posts
    217

    Re: Sand filter maintenance problem

    Dave and Richard, do you have top mount or side mount sand filters?

    Dave could you describe the process you go through to clean your filter? Do you actually remove the sand and sift it?
    19,600 gal, Vinyl, Grecian L, StaRite Dura-Glas 1 HP pump, 3/4hp booster, Pentair Clean and Clear 420 Cartridge filter
    The Pool Cleaner 4x, PoolSkim

  6. Back To Top    #6
    JasonLion's Avatar
    Join Date
    May 2007
    Location
    Silver Spring, MD
    Posts
    37,879

    Re: Sand filter maintenance problem

    There are instructions on cleaning a sand filter in this topic.
    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

  7. Back To Top    #7
    Puffin's Avatar
    Join Date
    Jul 2010
    Location
    Metro Atlanta, Georgia
    Posts
    217

    Re: Sand filter maintenance problem

    Ah ok, since he mentioned a sifter I though it was a different technique.
    19,600 gal, Vinyl, Grecian L, StaRite Dura-Glas 1 HP pump, 3/4hp booster, Pentair Clean and Clear 420 Cartridge filter
    The Pool Cleaner 4x, PoolSkim

  8. Back To Top    #8
    JasonLion's Avatar
    Join Date
    May 2007
    Location
    Silver Spring, MD
    Posts
    37,879

    Re: Sand filter maintenance problem

    A sifter can be handy if there is debris in the sand that doesn't float. Start with the water hose as described and by the time you are done with that you will have a good idea if you want/need a sifter.
    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

Posting Permissions

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