Become a TFP Supporter Pool Math Forum Rules Pool School
Results 1 to 11 of 11

Thread: Low Flow / Filter Obstruction?

  1. Back To Top    #1

    Low Flow / Filter Obstruction?

    Hello Experts, Masters, Enlightened ones, and generally anyone less frustrated than I,

    (That should cover almost everyone :P)

    I'm coming to you completely at my wits end here. The pump bucket does not stay more than 2/3 filled and it seems to me that there is little suction throughout the whole pool. Initially when I had this issue I opened up the filter and found that the disperser assembly had fallen into the pool filter. It hadn't been PVC Glued well (if at all) and the filter was just grabbing anything it could get.

    After fixing that and spreading the sand on the inside I notice the pump bucket fill up immediately. The pool showed excellent flow and life was good -- for a couple runs. After 2-3 runs the pump bucket dropped to 2/3 full again.

    If I open the filter and smooth over the sand removing the very slimy top layer I notice the pump bucket once again fills up to the top. It won't go 100% -- maybe 90%. I can't do that each time the pump should turn on though.

    I did notice that the Multiport valve drips here and there, though it's very small and slow. I changed the gasket inside of it and it hasn't stopped but there was a second gasket I didn't change. I was thinking about doing that too.

    I have attached pictures to this post to perhaps give you an idea on what's going on. Normally my Dad works on this setup but he's had to move to another state for a bit for work and I'm taking over the maintenance on his house. This is for his house, not a commercial site -- even though the unit says it's commercial.

    Thank you for reading here,
    Thank you for your time.
    G



  2. Back To Top    #2
    JasonLion's Avatar
    Join Date
    May 2007
    Location
    Silver Spring, MD
    Posts
    37,879

    Re: Low Flow / Filter Obstruction?

    What is your filter pressure? Do you see any churning/bubbling in the pump strainer basket, or just slowly filling up with air? How is the water pressure (subjectively) coming out of the return jets? And finally, what kind of pump do you have?
    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

  3. Back To Top    #3

    Re: Low Flow / Filter Obstruction?

    Jason,

    Thank you for your reply. I will try and answer your questions as best as I can.

    The filter pressure is between 30-40 psi -- usually. When I stop the filter the pressure remains. When I open the pump basket to clean it out, the pressure drops to 0. Air is let into the filter I'm guessing. When the pump turns on again afterwards I can see the pump try to fill the tank and the pressure fluctuates wildly from 0 --> 15 increasing slowly. The reason why is the inflow from the pool isn't enough to fill the bucket. Through a method of bleeding and starting a stopping the pump the bucket will fill and the filter will go to 30 - 40psi. Once there, it'll hold just fine.

    I don't think I see bubbling. I see it try to fill the basket with water but it's not enough for how much the pump is moving so it's constantly "pouring" from the pool into the bucket. There's a giant air bubble at the top that stays since there isn't enough water flow to remove it.

    The pressure from the return jets seem low to me. The pool doesn't move much when the pump is on. I can see that all jets of the pool are providing water and I can see the surface is disturbed but it used to be more I guess for the lack of better terms.


    The pump is a Sta-Rite Dura-Glas II Pumps.

    Once again thanks for your reply.

  4. Back To Top    #4
    Mod Squad Bama Rambler's Avatar
    Join Date
    Jun 2009
    Location
    SouthWest Alabama
    Posts
    22,347

    Re: Low Flow / Filter Obstruction?

    That pressure is on the high side of what we ever see.
    What's your pressure if you put the filter on recirc?
    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

  5. Back To Top    #5

    Re: Low Flow / Filter Obstruction?

    Bama, Jason,

    The highest pressure I've ever seen was 35. Though there's a new symptom that's come about (I feel like everything is falling apart on me). Today the pool exhibited little bubbles coming out of the pipes of the pool. I noticed the Multiswitch valve (5th picture) was leaking a bit. I'm going to see if I can change the gasket inside of it). I know this isn't a total fix but I think that's what's causing the little bubbles.

    I also am going to change the sand in the Unit. I found out they've never done it and it's been about 10 years now. From my understanding it should be changed once every 5-6 years.

  6. Back To Top    #6
    Mod Squad Bama Rambler's Avatar
    Join Date
    Jun 2009
    Location
    SouthWest Alabama
    Posts
    22,347

    Re: Low Flow / Filter Obstruction?

    Check your pressure on recirc and see what you get. Those gaskets aren't hard to change.
    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

  7. Back To Top    #7

    Re: Low Flow / Filter Obstruction?

    Bama, and Jason,

    After a weekend of work it turned out to be:

    The sand needing to be replaced.
    The dispersers were lose from the connection of the side of the pump. I had to open it and reapply PVC glue.


    After I replaced the sand in the filter, everything kicked on back the way we had it years ago. I believe there still may be some air being let in via some of the tubes to the chlorination unit but I will replace those and see if that'll fix it.

  8. Back To Top    #8

    Re: Low Flow / Filter Obstruction?

    I had the same problem exactly my solution was to clean the pump impeller of dog hair and gunk. Now I get jacuzzi power and whole pool circulation in less than 1 minute. You can check TURN OFF POWER TO PUMP take out strainer basket and feel inside hole going to pump do you feel gunk? Clean with coat wire hanger or remove all bolts and clean impeller fins.

  9. Back To Top    #9
    JasonLion's Avatar
    Join Date
    May 2007
    Location
    Silver Spring, MD
    Posts
    37,879

    Re: Low Flow / Filter Obstruction?

    A clogged impeller would not give a filter pressure of 35 psi. When the impeller is clogged, the filter pressure reads lower than normal.
    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

  10. Back To Top    #10
    mas985's Avatar
    Join Date
    May 2007
    Location
    Pleasanton, CA
    Posts
    11,490

    Re: Low Flow / Filter Obstruction?

    Quote Originally Posted by hewlett123
    The filter pressure is between 30-40 psi -- usually. When I stop the filter the pressure remains.
    If the filter pressure does not go to zero when the pump shuts off, it is usually a bad gauge.
    Mark
    Hydraulics 101; Pump Ed 101; Pump/Pool Spreadsheets; Pump Run Time Study; DIY Acid Dosing; DIY Cover Roller
    18'x36' 20k plaster, MaxFlo SP2303VSP, Aqualogic PS8 SWCG, 420 sq-ft Cartridge, Solar, 6 jet spa, 1 HP jet pump, 400k BTU NG Heater

  11. Back To Top    #11

    Re: Low Flow / Filter Obstruction?

    Quote Originally Posted by JasonLion
    A clogged impeller would not give a filter pressure of 35 psi. When the impeller is clogged, the filter pressure reads lower than normal.
    He said his pressure fluctuates from 0-15 psi which tells me hes got something in the line the pump is trying to deal with.

Posting Permissions

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