Closing an Empty Pool

dpcory

0
Sep 2, 2014
17
South Bend, IN
I just had the floor of my IG gunite pool painted with an epoxy coat and it is currently in the 7-day curing process. I want to take advantage of the fact that it is empty and blow out and seal all of the pipes before I refill the pool. The return lines and skimmer lines are not really any different from a normal closing after draining below them. But I'm wondering about the main drain line.

Is there any reason not to blow out the main drain line and put a rubber plug in it before refilling (other than the hassle of diving down and removing it in the spring)? The deep end is 8.5 feet.
 
Is there any reason not to blow out the main drain line and put a rubber plug in it before refilling (other than the hassle of diving down and removing it in the spring)? The deep end is 8.5 feet

If you blow out the MD without any water in it and plug it (creating an "air lock"), I do not believe this will do anything as the air will disappear because there is no water. I could be on the "wrong track", but this seems logical. Thank you.
 
Thanks for the responses. Sorry if the question was unclear - when i referenced "blowing out" the pipes, I just meant blowing any remaining water out with a shop vac. The pipes are all essentially empty now.

I'm really just curious if there is a difference between 1) filling the pool and then closing the MD using an air lock approach vs. 2) putting a rubber plug in it when it's empty so that when I refill it next week, no water will get in the MD line at all.

Option 2 seems easier since it's empty now but I'm just wondering if there is a reason not to do it this way (e.g. if rubber plugs are less reliable than the air lock approach).
 
Thanks for the responses. Sorry if the question was unclear - when i referenced "blowing out" the pipes, I just meant blowing any remaining water out with a shop vac. The pipes are all essentially empty now.

I'm really just curious if there is a difference between 1) filling the pool and then closing the MD using an air lock approach vs. 2) putting a rubber plug in it when it's empty so that when I refill it next week, no water will get in the MD line at all.

Option 2 seems easier since it's empty now but I'm just wondering if there is a reason not to do it this way (e.g. if rubber plugs are less reliable than the air lock approach).


I am curious to see what others say but i would think a rubber plug is far less likely to fail. If by some chance your valve failed and allowed the air out you would lose your airlock and the pipe would fill with water.
 
I'm really just curious if there is a difference between 1) filling the pool and then closing the MD using an air lock approach vs. 2) putting a rubber plug in it when it's empty so that when I refill it next week, no water will get in the MD line at all.

Where are you placing the plug? The main drain has a cover on it and usually can not be plugged (not that I know of).
 
My MD just has a plastic cover on it held on with screws and is off now for the painting. The pipe comes laterally out of the side of the drain unit and with the cover off, I can put a rubber plug in the lateral opening.

The pipe, with the cover off can be plugged. Although, are you planning on diving down to remove the plug in spring? If so, then this can be plugged. You also have to then put the screws back in. It is a little difficult to stay down there, because of gravity. Are you planning on filling the pool up all the way as well? If this was my pool, I would put everything back to normal, blow out the main drain and create the "air lock".

My friends cover actually comes off each year. Last year, when I blew air through the main drain, the cover came to the surface from the volume of air (Hello Cyclone!). Now he just puts it back. Essentially, he can dive down and plug the main drain and we can vacuum the water out. Never thought of this one. I would think this is also a safety feature to put the cover back on. His can not be fixed unless the whole pool is drained.
 

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This makes no sense to me. What do you picture filling the line after the air 'disappears'? I may simply be misunderstanding your point.

I believe he misunderstood my initial question and thought I was trying to create an air lock with an empty pool. Which is why I clarified what I meant by "blowing out and sealing all of the pipes." So he was saying there would be nothing to hold the air in the main drain line, then when I fill the pool the line will fill with water.
 
If you blow out the MD without any water in it and plug it (creating an "air lock"), I do not believe this will do anything as the air will disappear because there is no water. I could be on the "wrong track", but this seems logical. Thank you.

An airlock will be created by filling & closing/plugging the MD line ate the filter pad.


Sent from my iPhone using Tapatalk
 
Dpcory is mainly plugging the piping in the deep end and then filling up with water. This only complicates the issue in the spring when the main drain has to be opened. Unless, I missed something. It is possible, that pool owners go down to the bottom drain and plug the piping, but have never seen or heard of this. I have 3 friends that close and open a lot of pools (side business) all year long and they also close the MD from the pad with an "air lock". No one has requested that they dive in the pool and plug the piping (after removing the cover). Thanks!
 
I had the brilliant idea earlier in the year to take my MD cover off to troubleshoot a clog issue and ill tell you, getting the cover back on (at least mine had an accordion like piece that needed to be compressed) and keeping it in the right orientation and not dropping the screws in the drain and turning them while trying not to float away at the bottom of a 5' deep end while holding my breath for a minute at a time was an absolute nightmare and will never ever happen again. Unless you own scuba gear you're in for a bad time trying to put that cover on later when the pool is full
 
I decided to stick the rubber plug in the main drain, blow some air in from the other side with my leaf blower (not sure if this was necessary) and shut the valve. Then the plan was to put some water back in the pool, pull the plug and I would have my air lock. Mostly I was trying to avoid the need for an air compressor. I have access to one but this would save me some time if I didn't have to go pick it up and return it.

As the pool was filling up, the thought crossed my mind to just leave the plug in until spring. Then I read zolakk's comment and decided against that - and I'm glad I did. There was about 5 feet of icy water in the deep end of the pool at the time. I dove in and was able to get the plug out pretty easily. But then I had to get the MD cover on. It was not easy and I would've had a much worse time but thankfully I've been tooling around with my mesh cover and it was floating on the top of the water at the time. So I was able to put my foot on it from underneath to stabilize myself as I lined the cover up and screwed it in. Still, it probably took me 15 "dives" to get it done, and I was shivering the rest of the day.

I guess the moral of the story is if your pool is empty when you are getting ready to close and this thought crosses your mind (assuming I'm not the only one that would get this bright idea), just fill the pool and borrow / rent the air compressor.

Thanks for your help Catanzaro and zolakk.
 
Thanks for following up and reporting back on your less-than-pleasant experience! Hopefully it will help a future reader.

Probably a dumb question, but why wouldn't it just have worked to close the valve near the pump end, and then put water in the pool (without doing anything at all at the main drain)? If the line is full of air to start with, and if the main drain is the lowest point in the line, it seems to me that the water pouring into the pool wouldn't displace the air in the line, since that air has no place to go (valve closed at upper end).
 
I guess the moral of the story is if your pool is empty when you are getting ready to close and this thought crosses your mind (assuming I'm not the only one that would get this bright idea), just fill the pool and borrow / rent the air compressor.

Thanks for your help Catanzaro and zolakk.

There has to be a friend or neighbor will to help you out with there air compressor. Hopefully next year. With my neighbor, we sometimes share tools. Make's life easier. :D
 
Probably a dumb question, but why wouldn't it just have worked to close the valve near the pump end, and then put water in the pool (without doing anything at all at the main drain)? If the line is full of air to start with, and if the main drain is the lowest point in the line, it seems to me that the water pouring into the pool wouldn't displace the air in the line, since that air has no place to go (valve closed at upper end).

Not a dumb question at all. You're probably right and I over-thought it but I am fairly new to this (2nd year closing my pool after buying a new house) and I'm not 100% sure how the MD piping is run. Most likely the MD is the lowest point (rather than the lines running level and then up to the pump) but I wanted to be 100% sure I had the air lock. Next year it won't be empty (I hope) and I'll try the air compressor method.
 
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