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Thread: Should I keep my main drain valve open??

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    Join Date
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    Should I keep my main drain valve open??

    My pool has a 3HP Intelliflow VS pump. I have dedicated piping for the main drain and each skimmer. My pool builder said I should keep the main drain valve 100% open and the two skimmer valves about 50% open. When the pool runs in pool mode(1800 rpm) I get almost no visible draw into the skimmers. When the pool runs in clean mode(3000 rpm) I can see a little bit of draw coming from the skimmers but not enough to draw floating debris into them.

    I can shutoff the main drain and get tons of suction into the skimmers to pull in debris. How important is it to keep the main drain open during routine cleaning cycles? My thought is that its better to continue to draw debris into the skimmers instead of letting it sink and wait for the robot to suck it up.

    Thoughts on the best way to keep the valves set.

    Thanks!
    Gunite Pool/Spa, CLI Caribbean blue crystal stone smooth, Pentair 3hp Intellifo VS, Pentair Quad DE Filter, Pentair 400k BTU Heater, KK Prowler 820, Pentair PSL4 controler with Screenlogic wifi, Inline Chlorinator, Pentair 1.5hp Spa Blower, TF-100 Test Kit w/ Speed Stir. My 2016 Pool Build

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    Texas Splash's Avatar
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    Re: Should I keep my main drain valve open??

    I'm with you. I'd rather pull the debris off the water before it settles if possible. For times when I might need to brush fine dust and particles along the bottom, I can always increase MD flow at that time.
    Pat (a.k.a. Texas Splash) ~ My Pool: Viking Fiberglass; 17,888 Gal; Waterway Supreme 2-sp/2-hp pump; Hayward Ctg filter; TF-100 w/ Speed Stir
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    mas985's Avatar
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    Re: Should I keep my main drain valve open??

    +1 MDs are almost worthless for daily use.
    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

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    Re: Should I keep my main drain valve open??

    Quote Originally Posted by mas985 View Post
    +1 MDs are almost worthless for daily use.
    Thanks - I'll probably keep it closed from now on and only open up when brushing the pool.
    Gunite Pool/Spa, CLI Caribbean blue crystal stone smooth, Pentair 3hp Intellifo VS, Pentair Quad DE Filter, Pentair 400k BTU Heater, KK Prowler 820, Pentair PSL4 controler with Screenlogic wifi, Inline Chlorinator, Pentair 1.5hp Spa Blower, TF-100 Test Kit w/ Speed Stir. My 2016 Pool Build

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    mas985's Avatar
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    Re: Should I keep my main drain valve open??

    Just be careful brushing large debris towards the MD. It can get clogged easily and difficult to clear.
    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

  6. Back To Top    #6

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    Re: Should I keep my main drain valve open??

    Quote Originally Posted by mas985 View Post
    Just be careful brushing large debris towards the MD. It can get clogged easily and difficult to clear.
    10-4, just bird poop
    Gunite Pool/Spa, CLI Caribbean blue crystal stone smooth, Pentair 3hp Intellifo VS, Pentair Quad DE Filter, Pentair 400k BTU Heater, KK Prowler 820, Pentair PSL4 controler with Screenlogic wifi, Inline Chlorinator, Pentair 1.5hp Spa Blower, TF-100 Test Kit w/ Speed Stir. My 2016 Pool Build

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    Re: Should I keep my main drain valve open??

    I wish my main drain was still working. Apparently the last time the skimmer was replaced they abandoned the main drain line that ran to the bottom of the skimmer, so now its 100% surface draw. If I had say 10% flow from the MD it would pull in the random small debris and keep the water better circulated in the deep end.
    20x35 in-ground oval. Wet Edge Luna Quartz finish. Hayes Super Pump with AO Smith V-Green 165 VS motor. Polaris 380. Enersol solar heating with automatic controller. Automated chlorination with Stenner pump.

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    Re: Should I keep my main drain valve open??

    P5080116.jpg

    Keep at least partly open to avoid this
    Doug - Purchased 1/2016, 1995 house with 16x31 ft, ~23000 gallon Gunite pool w 11x7 spa, 3 Pentair VS pumps, a boost pump for polaris 3900 and a BaduŽ Jet super-sport swim jet pump, 1.5 hp blower, a CL460 Cartridge filter. TF-100 test kit. Aquapure SWG, iAqualink - Lots to learn. New Aquabright, Jandy LEDs, CMP LED Sheers.

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