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Thread: Main Drains Not Working

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    Main Drains Not Working

    Hello!

    New to the forum and new to being a pool owner. We moved into a house with an In-ground marcite pool of around 15,000 gallons. There are two main drains at the bottom of the deep end that are not sucking. I'm assuming they are plumbed together. Just off the pool concrete is some PVC pipe that comes up and isn't hooked up to anything. I pushed water through this tube and it came out of the main drains at the bottom so now I'm left to believe that the drains aren't hooked up. Right next to this 2" PVC pipe is a capped off 1.5" PVC pipe that I'm assuming goes to the pump. You can see this pipe in the picture attached at the bottom left of the picture. Before I go hooking this back up, I have a few questions. Why would one side be 2" and the other 1.5"? Is there typically a filter basket here above ground because the main drains suck more? I have not removed the cap from the 1.5" side yet. I don't want to do that till I'm ready to reconnect. Any help would be great!!
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    Mod Squad Jimrahbe's Avatar
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    Re: Main Drains Not Working

    Hi Walt,

    Interesting problem. I can't think of any reason the main drain plumbing would come up out of the ground until in got back to the equipment pad. While it could be someone's attempt to repair the main drain, my guess is it has to do with an old safety devise to prevent anyone from getting stuck on the main drain. But that is just a guess...

    Generally, when the main drain is disconnected, it is because it is plugged or it leaks. That said, I have pools at two rent house and neither of them have working main drains and it does not seem to make any difference.

    So, I have a couple of questions for you..

    1. How did you initially determine that the main drains were not working?

    2. Does your equipment pad have a valve that allows you to select the main drain. A picture of the pad would be great.

    3. What advantage will a working main drain provide you?

    Jim R.
    Finished in 2015 - 17K Gal, IG, 20' x 25' Almost Rectangular Pool, Pebble finish, three rockport water falls. Pentair Equipment: EasyTouch 4, IC40 SWG, 3 HP VS Pump, CCP520 Cartridge Filter.
    TF100 with SpeedStir and SampleSizer, ColorQ Pro 7, Dolphin Premier Robot Cleaner, added Screen Logic 2, added small 3 person Calder Spa.

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    Re: Main Drains Not Working

    Quote Originally Posted by Jimrahbe View Post
    Hi Walt,

    Interesting problem. I can't think of any reason the main drain plumbing would come up out of the ground until in got back to the equipment pad. While it could be someone's attempt to repair the main drain, my guess is it has to do with an old safety devise to prevent anyone from getting stuck on the main drain. But that is just a guess...

    Generally, when the main drain is disconnected, it is because it is plugged or it leaks. That said, I have pools at two rent house and neither of them have working main drains and it does not seem to make any difference.

    So, I have a couple of questions for you..

    1. How did you initially determine that the main drains were not working?

    2. Does your equipment pad have a valve that allows you to select the main drain. A picture of the pad would be great.

    3. What advantage will a working main drain provide you?

    Jim R.

    Jim thanks for the response!

    1. I found that they weren't sucking just by swimming in the pool. I would put my feet on the drain and there was no suction.

    2. There is a valve at the equipment pad for both the main and skimmer drains. I would upload a picture but it looks like two is my max. Not sure if the pictures in my original post would be gone if I deleted them from my picture database. There is also a solar system connected after the filter.

    3. I have a good thing going on the surface of the pool as far as leaf collection but the bottom of the pool doesn't get the same love. I would like to be able to brush the floor of the pool and I feel like having the mains connected would help with that cleanliness. It is way easier to brush than to vacuum.

    I still can't think why the piping would change from 1.5" to 2".

    Walt

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    mas985's Avatar
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    Re: Main Drains Not Working

    I found that they weren't sucking just by swimming in the pool. I would put my feet on the drain and there was no suction.
    You shouldn't feel any suction. That is the way they are designed if VGBA compliant.

    The main drains really have only one purpose and that is to draw water from the bottom of the pool and recirculate that water to other parts of the pool. They do not clean very well nor should you expect them too.

    I would like to be able to brush the floor of the pool and I feel like having the mains connected would help with that cleanliness. It is way easier to brush than to vacuum.
    Don't try that with any sort of leaves or large debris as that could easily clog up the main drains. At best, they can only really handle very fine dirt.

    If they are disconnected, I wouldn't bother reconnecting them. MDs are pretty useless and many new pools are being built without them:

    http://apsp.org/portals/0/PDFs/Case%...n%20Drains.pdf
    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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    Mod Squad kimkats's Avatar
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    Re: Main Drains Not Working

    I will tell you that I KNOW my main drain "works" as in it does draw water BUT it does not really "suck" Even when I have my skimmer valve shut off so the pump is only drawing from the main drain I can put my feet, hand, left, whatever and it will not pull or hold it on the drain top AND I only have one drain.

    As for the pipe set up..........there was another pool that had something kind of like that.........I will have to think about who it was and why it was......it did not have anything to do with the main drain.

    Kim

    - - - Updated - - -

    Pictures-----use photo bucket with the img link and you should be able to add more pics. OR you can become a supporting member and get more storage.

    Kim
    TFP Moderator 33x52 round AG 25,600 gals Sand Filter 1.5hp Pump - 2 Speed, SLAM, Pool School, Recommended Levels, Recommended Chemicals, Pool Math, Chlorine/CYA Chart, TF-100 Test Kit

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    Re: Main Drains Not Working

    Mark and Kim,

    lots of of good info here thank you very much. So to leave the mains disconnected would be alright? That only leaves one place where suction occurs and that is the skimmer. There is also a port about two feet from the skimmer where you would connect a vacuum or cleaner. I have that capped unless I am vacuuming. Should I leave that port open? Is the only way to keep the pool sparkling clean is to vacuum it? I am a-ok with this, just new to the process. Once a week is enough you think?

    Again, I appreciate all the help!! I'm slowly learning.

    Walt

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    mas985's Avatar
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    Re: Main Drains Not Working

    So to leave the mains disconnected would be alright?
    Yes

    Should I leave that port open?
    You don't have to.

    Is the only way to keep the pool sparkling clean is to vacuum it?
    Mostly. You can use a leaf rake to remove leaves and you might want to think about an automatic cleaner. Cleaning frequency is entirely up to you and your tolerance for dirt on the bottom of the pool.
    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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    Mod Squad Jimrahbe's Avatar
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    Re: Main Drains Not Working

    Walt,

    Most people have some type of automated cleaner. In your case a "Suction" side cleaner or Robot. I have robots in my pools and like them way better than the suction side cleaners.

    I am much too lazy to hook up and use a manual hose and vacuum system.

    If you set your valve to Main Drain only, or maybe mostly Main Drain, and your pump does not immediately run out of water, then you can assume that your main drains are connected and basically functioning.

    Jim R.
    Finished in 2015 - 17K Gal, IG, 20' x 25' Almost Rectangular Pool, Pebble finish, three rockport water falls. Pentair Equipment: EasyTouch 4, IC40 SWG, 3 HP VS Pump, CCP520 Cartridge Filter.
    TF100 with SpeedStir and SampleSizer, ColorQ Pro 7, Dolphin Premier Robot Cleaner, added Screen Logic 2, added small 3 person Calder Spa.

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    Mod Squad kimkats's Avatar
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    Re: Main Drains Not Working

    Pool School - Basic Pool Care Schedule

    This link should be very helpful for you. I have it printed out and in the lid of my test kit.

    Kim
    TFP Moderator 33x52 round AG 25,600 gals Sand Filter 1.5hp Pump - 2 Speed, SLAM, Pool School, Recommended Levels, Recommended Chemicals, Pool Math, Chlorine/CYA Chart, TF-100 Test Kit

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