# Swimming pool drains
**URL:** https://boards.straightdope.com/t/swimming-pool-drains/336573
**Category:** Factual Questions
**Created:** [December 21, 2005, 2:54am UTC](https://boards.straightdope.com/t/swimming-pool-drains/336573 "2005-12-21T02:54:09Z")
**Posts on this page:** 12
**Page:** 1
### Author:  [@snailboy](https://boards.straightdope.com/u/snailboy)
#### Post date: [December 21, 2005, 2:54am UTC](https://boards.straightdope.com/t/swimming-pool-drains/336573/1 "2005-12-21T02:54:09Z")
You know those drains at the bottom of underground swimming pools? (I assume they’re drains anyway. They don’t exactly look like a bathtub stopper, but I don’t know what else would be down there.) Are you supposed to swim down there to open it, or poke at it with a stick from outside the pool or what? How much pressure is there under 12 feet of water and how hard is it to avoid the suction? I remember swimming at the bottom of a pool as a kid and wondering this stuff, but being too scared to even touch it from fear of getting stuck down there. My fellow dopeheads, ease my fear of swimming pool drains (or justify it).
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### Author:  [@Squee](https://boards.straightdope.com/u/Squee)
#### Post date: [December 21, 2005, 3:08am UTC](https://boards.straightdope.com/t/swimming-pool-drains/336573/2 "2005-12-21T03:08:27Z")
> [@snailboy](#):
>
> You know those drains at the bottom of underground swimming pools? (I assume they’re drains anyway. They don’t exactly look like a bathtub stopper, but I don’t know what else would be down there.) Are you supposed to swim down there to open it, or poke at it with a stick from outside the pool or what? How much pressure is there under 12 feet of water and how hard is it to avoid the suction? I remember swimming at the bottom of a pool as a kid and wondering this stuff, but being too scared to even touch it from fear of getting stuck down there. My fellow dopeheads, ease my fear of swimming pool drains (or justify it).
Thought this is secondhand anecdotal evidence, I still have to say I agree with my friend…
He was a lifeguard in training and was told that someone had their intestines sucked outward by sitting close to an open pool drain.
I guess I believe it because I can believe a drain sucking out the water of a large sized pool can pull that kind of suction. I know I shouldn’t quote stuff like that in GQ, but he was pretty convincing in knowing what he was talking about, urban legend or not.
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### Author:  [@Squink](https://boards.straightdope.com/u/Squink)
#### Post date: [December 21, 2005, 3:13am UTC](https://boards.straightdope.com/t/swimming-pool-drains/336573/3 "2005-12-21T03:13:06Z")
[Complete Evisceration of the Small Intestine through a Perianal Wound as a Result of Suction at a Wading Pool.](http://www.jtrauma.com/pt/re/jtrauma/abstract.00005373-200108000-00033.htm;jsessionid=DoGYMSuClOmptuoiOJSxKEZAchArHm6q2wfaJwlpVKxrIF1IRGBd!-1432726313!-949856145!9001!-1)
From the charmingly named site [hotelfun4kids](http://www.hotelfun4kids.com/travelnews/safetynews/pools.htm):
> [@](#):
>
> Since 1980, CPSC knows of 18 incidents, including five deaths, involving children between the ages of two and 14 who were injured or died due to body part entrapment involving the drain of a swimming pool, wading pool, or spa. In addition, last week, a 16-year-old New Jersey girl drowned when her body was sucked down against a drain on the bottom of a spa. Her body apparently formed a vacuum seal against an outlet for circulating water and she was held underwater.
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### Author:  [@Philster](https://boards.straightdope.com/u/Philster)
#### Post date: [December 21, 2005, 3:15am UTC](https://boards.straightdope.com/t/swimming-pool-drains/336573/4 "2005-12-21T03:15:07Z")
Absolutely dangerous. Children have become stuck. Intestines have been sucked out. Although, the old style smaller drains without a cap and used in hot tubs are the really dangerous ones, with a reputation for literally sucking out intestines and/or causing death. Some area laws require emergency shut down switches nearby, and caps on the drain that force side flow, really limiting the chances of a vacuum seal.
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### Author:  [@Philster](https://boards.straightdope.com/u/Philster)
#### Post date: [December 21, 2005, 3:18am UTC](https://boards.straightdope.com/t/swimming-pool-drains/336573/5 "2005-12-21T03:18:13Z")
> **[Pool & Spa Entrapment - Lifesaving Resources](https://lifesaving.com/issues-safety-rescue/pool-spa-entrapment/)**
>
> This article discusses the possibility of entrapment in pool and spa filtration systems, and recommends guidelines to prevent accidental entrapment.
Cases not for the squeamish.
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### Author:  [@snailboy](https://boards.straightdope.com/u/snailboy)
#### Post date: [December 21, 2005, 11:47am UTC](https://boards.straightdope.com/t/swimming-pool-drains/336573/6 "2005-12-21T11:47:44Z")
Okay, so it looks like they’re dangerous after all. What’s the proper way to open one though?
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### Author:  [@minor7flat5](https://boards.straightdope.com/u/minor7flat5)
#### Post date: [December 21, 2005, 12:58pm UTC](https://boards.straightdope.com/t/swimming-pool-drains/336573/7 "2005-12-21T12:58:03Z")
Why would you want to open it? An attempt to empty the pool?
Usually the thing that is at the bottom that sucks intestines out is an inlet for the filter pump, and not a drain. (Whenever I hear the intestine stories, I recall the pleasant sensation of sitting on a inlet grate at the bottom of a hotel pool at a tender age. Glad I survived it)
About emptying pools:
You rarely need to. The water in my pool was left unchanged for over a decade, of course there was constant replenishment for evaporation and the like. Many in-ground pools (mine included) cannot stay empty for long because of the ground water forces on the outside.
When you decide one fine day that it’s time to drain the pool, it isn’t going to be as easy as pulling a plug since the bottom of your pool is pretty darned deep. The process usually involves a pump.
The guys who changed my liner last summer simply tossed a sump pump with a long hose into the deep end and left it running all day. I suppose that if you have the scary filter inlet grate at the bottom of the pool all one needs to do is redirect the filter output to “waste” and run the filter pump until the pool is empty.
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### Author:  [@Mr.Goob](https://boards.straightdope.com/u/Mr.Goob)
#### Post date: [December 21, 2005, 2:31pm UTC](https://boards.straightdope.com/t/swimming-pool-drains/336573/8 "2005-12-21T14:31:50Z")
I have a gunite plaster lined inground pool. It’s 10 feet deep at the drain by the diving board. The drain there and the one in the skimmer box ar the inlets for the filter.
There is no open or closed, it’s like the drain on the bottom of a sink, except it’s connected in a closed system to the filter pump. Unless the pump is running, there is no suction. IIRC it’s a 1.5 horsepower motor on the pump. The suction isn’t all that great, you can put your hand on it and pull away with little effort. The smaller 2" opening at the bottom of the skimmer feels like it could suck your arm in. They both have the same draw but the size of the drain makes a difference on how much suction there is.
For my **home pool** I can’t see anyone but maybe an infant\* being sucked tight against the bottem drain.
\*not going to happen, my house rule for babies is 2 adults per child in the water.
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### Author:  [@Philster](https://boards.straightdope.com/u/Philster)
#### Post date: [December 21, 2005, 4:05pm UTC](https://boards.straightdope.com/t/swimming-pool-drains/336573/9 "2005-12-21T16:05:02Z")
:eek:
When you form a complete covering of the filter opening, or when hair becomes entangled you have big problems, so ignore the cavaliere post preceding this one!!
In system where the top ‘skimmer’ is closed (and people do that), there is no point in the system where the vacuum lock can be broken when someone is sucked onto the bottom inlet (which now has all the oomph).
Hair is often a culprit, and while hair entanglement does not = intestinal problems, death by drowning tends to overwhelm that point.
If ever a post could be deleted, the one before this one should be.
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### Author:  [@AskNott](https://boards.straightdope.com/u/AskNott)
#### Post date: [December 21, 2005, 4:42pm UTC](https://boards.straightdope.com/t/swimming-pool-drains/336573/10 "2005-12-21T16:42:48Z")
I lived in a house with an indoor pool when I was a kid. The suction on the drain was not sufficient to be dangerous. I remember swimming to the bottom and letting the drain “grab” my hand, and I could pull it back off.
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### Author:  [@N9IWP](https://boards.straightdope.com/u/N9IWP)
#### Post date: [December 21, 2005, 6:55pm UTC](https://boards.straightdope.com/t/swimming-pool-drains/336573/11 "2005-12-21T18:55:27Z")
Some building codes require two intake drains. On some home show I saw this implemented as two 1.5 in pipes about 18 inches apart.
Brian
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### Author:  [@snailboy](https://boards.straightdope.com/u/snailboy)
#### Post date: [December 22, 2005, 12:36am UTC](https://boards.straightdope.com/t/swimming-pool-drains/336573/12 "2005-12-22T00:36:42Z")
> [@minor7flat5](#):
>
> Usually the thing that is at the bottom that sucks intestines out is an inlet for the filter pump, and not a drain.
Well that explains it right there. I had thought the only filter inlets were the ones at the surface of the water. I could see major suction happening if the other inlets were closed. I don’t guess I’d have to worry about accidentally opening any drain though. Thanks.