Become a TFP Supporter Pool Math Forum Rules Pool School
Results 1 to 5 of 5

Thread: Use of main drain to control flow

  1. Back To Top    #1
    Mattsway's Avatar
    Join Date
    Apr 2017
    Location
    Sussex UK
    Posts
    30

    Use of main drain to control flow

    Hi, I'm running my pump 24/7 during my first SLAM and all is moving in the right direction.

    The problem is, I have a small suction leak and am spending ages bleeding the air, especially in the morning.

    I have slowed the leak by only using the main drain to the pump, so the skimmer valve is closed because that's where most of the air was leaking in.

    Can I further slow the leak by partially closing the main drain? Would doing that make a difference, or would the reduced pressure reduce the efficiency of the bleeding?
    My pump is oversized by design to give the fast turnover that might be needed in a hydrotherapy pool used by my disabled son. I was thinking that I could reduce the flow rate now there is a zero bather load. The usual pressure at the filter is 16psi.

    The suction pipework is inaccessible to me and the builders aren't available to fix it for a while, which is no problem with usual use of the pump of max 3hours a day, needing only 1/2 hour bleeding.
    In ground hydrotherapy pool in wooden cabin. Oil heater for water temp 89f. Poly Bloc construction using high temp liner. 9'9" square x 3'8" deep, 2700 gallons. Hayward MaxFlo XL pump, model SP2310XE161 0.97hp. Waterco Multicyclone 12 Plus Centrifugal Filter, guage reads 16psi. Certikin Skimmer with floating collar Weir. Spectrum UV light, Calorex 33 dehumidifier and 2 radiators in cabin. Taylor K2006C test kit.

  2. Back To Top    #2
    Mattsway's Avatar
    Join Date
    Apr 2017
    Location
    Sussex UK
    Posts
    30

    Re: Use of main drain to control flow

    Related to the above, do I need to have the pump running 24/7 during the SLAM given that the water is clear? Once the chlorine is mixed in after a full turnover, does it need constant circulation to react with the organisms in the water? Just a newbie's brain ticking over...Possibly completely wrong.
    In ground hydrotherapy pool in wooden cabin. Oil heater for water temp 89f. Poly Bloc construction using high temp liner. 9'9" square x 3'8" deep, 2700 gallons. Hayward MaxFlo XL pump, model SP2310XE161 0.97hp. Waterco Multicyclone 12 Plus Centrifugal Filter, guage reads 16psi. Certikin Skimmer with floating collar Weir. Spectrum UV light, Calorex 33 dehumidifier and 2 radiators in cabin. Taylor K2006C test kit.

  3. Back To Top    #3

    In the Industry

    duraleigh's Avatar
    Join Date
    Apr 2007
    Location
    Sebring, Florida
    Posts
    30,961

    Re: Use of main drain to control flow

    Keep your pump running until you complete the SLAM.

    Is the water level in the pool high enough to keep the skimmer(s) from sucking air? Why do you think it is the underground pipe from the skimmers causing the air intake?......it rarely is the cause.
    Dave S.
    42k vinyl and concrete pool, 1.5hp pump, 140gpm filter
    TFTestkits , PoolMath , Pool School

  4. Back To Top    #4
    Mod Squad pooldv's Avatar
    Join Date
    Aug 2012
    Location
    DFW, TX
    Posts
    24,974

    Re: Use of main drain to control flow

    It is generally best not to try to choke the flow down on the suction side of the pump. There is risk of cavitation and pump damage
    TFP Moderator
    If TFP helped you or saved you money - Become a TFP Supporter! <--Click here
    2012 build and pics, 20k gal gunite, black onyx pebblesheen, OK flagstone, IntellifoVS, cart filter w/Pleatco, IC40 SWG, Solartouch, 5 12'x4' solar panels, HP50HA heat pump, 8mil solar cover, borates, TF-100 test kit, SONOS, Doheny's Discovery Robot, hot tub on bleach

  5. Back To Top    #5
    Mattsway's Avatar
    Join Date
    Apr 2017
    Location
    Sussex UK
    Posts
    30

    Re: Use of main drain to control flow

    Quote Originally Posted by duraleigh View Post
    Keep your pump running until you complete the SLAM.

    Is the water level in the pool high enough to keep the skimmer(s) from sucking air? Why do you think it is the underground pipe from the skimmers causing the air intake?......it rarely is the cause.
    Please see my last post for the suspected cause;

    Air in pump when heating on?

    Water level is half way up the skimmer. I have lubed all o rings and run water over the pump lid and suction pipework without success. I also tried cling film and smoke to check for air getting sucked in. Shutting off the skimmer line slowed the rate at which the pump sucked air. The suction pipework at the skimmer end is under plywood, the top of which is covered by the vinyl covering the pool.

    - - - Updated - - -

    Quote Originally Posted by pooldv View Post
    It is generally best not to try to choke the flow down on the suction side of the pump. There is risk of cavitation and pump damage
    Thanks for this. I'll leave it fully open.
    In ground hydrotherapy pool in wooden cabin. Oil heater for water temp 89f. Poly Bloc construction using high temp liner. 9'9" square x 3'8" deep, 2700 gallons. Hayward MaxFlo XL pump, model SP2310XE161 0.97hp. Waterco Multicyclone 12 Plus Centrifugal Filter, guage reads 16psi. Certikin Skimmer with floating collar Weir. Spectrum UV light, Calorex 33 dehumidifier and 2 radiators in cabin. Taylor K2006C test kit.

Posting Permissions

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