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

Thread: observation on a "weak" main drain

  1. Back To Top    #1

    Join Date
    May 2009
    Location
    Dallas, TX
    Posts
    781

    observation on a "weak" main drain

    When I first took over the pool I assumed the main drain line was plugged because I could swim right up to it with pump running, place my hand directly over the cover, and feel not one whit of suction. Then as time went by I realized it must have some degree of suction because I noticed leaves congregating over the cover when pump was running. But still I considered it a minimal source of suction in the system.

    So today as I was performing routine maintenance, I notice the pump strainer basket is *crammed* with big pecan leaf stems that could only have come from the main drain. They don't float because they are heavy, and besides, there were none in the skimmer basket. So long story short, main drain is obviously operating normally. But I tell you, you can feel not the slightest whim of suction if you hold your hand over it! How it is able to not only draw in, but suck the big stems all the way up to strainer basket is beyond me!

    Anyhoo, carry on...just an observation...
    20K gal IG plaster pool, Manually chlorinated with 6% bleach, 1.5 HP Sta-Rite Dura-Glas II pump, Pentair FNS Plus 48 DE filter, Polaris 280

  2. Back To Top    #2
    Mod Squad jblizzle's Avatar
    Join Date
    May 2010
    Location
    Tucson, AZ
    Posts
    37,389

    Re: observation on a "weak" main drain

    That is the way the drain covers are designed ... so that you do not feel suction which could lead to entrapment. I have observed the same thing.

    Posted from my Droid with Tapatalk ... sorry if my response is short
    Jason, TFP Moderator
    18k IG pebblesheen pool, Hayward ProLogic P4 w/ T-15 SWG, Pentair 1HP 2-speed Superflo, Hayward 6020 DE filter
    500 sqft Heliocol solar panels, ThePoolCleaner, TF-100 test kit w/ SpeedStir
    Pool School + Test Kit + PoolMath = A TROUBLE FREE POOL
    If you found TFP helpful and we saved you money ... Become a TFP Supporter!

  3. Back To Top    #3

    Join Date
    May 2009
    Location
    Dallas, TX
    Posts
    781

    Re: observation on a

    Quote Originally Posted by jblizzle
    That is the way the drain covers are designed ... so that you do not feel suction which could lead to entrapment. I have observed the same thing.

    Posted from my Droid with Tapatalk ... sorry if my response is short
    Thanks for that jblizzle, but just to be clear, mine is an old style drain cover, not one of the newer anti-entrapment jobbies. Still I get what you're saying...just seems counter-intuitive.
    20K gal IG plaster pool, Manually chlorinated with 6% bleach, 1.5 HP Sta-Rite Dura-Glas II pump, Pentair FNS Plus 48 DE filter, Polaris 280

  4. Back To Top    #4
    Mod Squad jblizzle's Avatar
    Join Date
    May 2010
    Location
    Tucson, AZ
    Posts
    37,389

    Re: observation on a "weak" main drain

    I am not sure my single drain is compliant either. Previous house had 2 floor drains which reduces the flow feel even more.

    Posted from my Droid with Tapatalk ... sorry if my response is short
    Jason, TFP Moderator
    18k IG pebblesheen pool, Hayward ProLogic P4 w/ T-15 SWG, Pentair 1HP 2-speed Superflo, Hayward 6020 DE filter
    500 sqft Heliocol solar panels, ThePoolCleaner, TF-100 test kit w/ SpeedStir
    Pool School + Test Kit + PoolMath = A TROUBLE FREE POOL
    If you found TFP helpful and we saved you money ... Become a TFP Supporter!

  5. Back To Top    #5
    UnderWaterVanya's Avatar
    Join Date
    Jun 2012
    Location
    Mint Hill, NC
    Posts
    2,589

    Re: observation on a "weak" main drain

    My main drain is like yours also; old and does not have feel like much suction is there. My guess is that many older designs are perfectly fine but the manufacturer is not going to go back and certify something no longer made.

    Sent via Tapatalk...
    Inlaws Pool Boy since June 14th 2012, Pool built ~ 2003, In-Ground, 16'x32'
    13500 gal, Vinyl Liner, Fiberglass Slide, TF-100 Test Kit, Hayward 210T
    sand filter, A.O. Smith 1.5HP main pump motor (C48L2N134C1),
    Hayward SuperPump (model ?), Polaris 380 & PB4 Booster Pump

Posting Permissions

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