Winterizing bottom drain in Canada.

ndk1

New member
Sep 18, 2010
1
Hello all.

It is once again that time of year. We had a great summer and lots of fun in our pool.
I am new posting here so I did a search in order to confirm that this hasn't been posted before.

What is the best way to winterize the bottom drain of a pool? Antifreeze? Is there a way to cover it and drain it? Blow air out of it?

I am completelty lost and there is not a lot of info i can find anywhere. I lost a pool last year (still not sure what happened)m and I suspect it was the bottom drain.

Please, any advice appreciated.

Cheers:)
 

4JawChuck

Well-known member
Jun 13, 2010
223
Winnipeg, Manitoba, Canada
I am curious over this issue also, I expect my pool to freeze completely to the bottom (few weeks of -40C temps for sure) and the only thing I could think of that would isolate the bottom drain is a tube extending above the water line that was rubber sealed or gasketed to the drain cover. Once you pumped the water out of the tube water pressure would hold it in place I imagine.

I could find no information on the web anywhere that addresses this issue, do people actually just fill the line with antifreeze and hope for the best or seal the drain cover and then fill?

Inquiring minds want to know?
 
I also live in Winnipeg. When the guy who does our winterization for us he simply blows air through the main drain for several minutes. Once there is significant air bubbling up from the main drain he closes the valve at the pump to 'lock in the air' in the main drain line. This seems to work fine for us.

Although it gets pretty cold up here for extended periods I'm not certain if an 8 foot deep pool would actually freeze to the bottom.

Good luck with your winterization.
 

mart242

LifeTime Supporter
May 3, 2010
153
Ottawa, ON, Canada
So antifreeze is useless? That's what my poolbuilder did last year, poured a jug of antifreeze down the main drain (through the pump). Would a 5hp shopvac be strong enough to blow the main drain line?
 

Hotrod30

Platinum Supporter
LifeTime Supporter
Dec 22, 2007
504
Central New York
I'll put my 2 cents in for the heck of it. I DON'T blow out the bottom drain with air. The reason is because of the unknown torque it could cause on the bottom drain and line in a sand bottom pool. The pool level and the level in the drain line should be about equal with an open line at the pump. If you were there when the pool was built; you should have an idea how the line comes up from the drain to the pump. Mine comes straight up from the deep end to the pump house with no parallel running with ground level.

I pour 2 gallons of anti-freeze slowly in the open line at the pump house to due the bottom drain line. Anti-freeze will mostly float on water; pouring slowly will help keep it in the line. Then I close the line and also close the valve to the bottom drain so the line is sealed in the pump house.

Of course, it is the way I do it (not the only way). I'm in growing zone 4b; which is Winter to -25 deg F. I use 22 gallons of anti-freeze when I close my pool. It cheaper than digging up a line in the Spring.
 

mart242

LifeTime Supporter
May 3, 2010
153
Ottawa, ON, Canada
Hotrod30 said:
Anti-freeze will mostly float on water; pouring slowly will help keep it in the line. Then I close the line and also close the valve to the bottom drain so the line is sealed in the pump house.
Hmm the pool store where I attended the "how to close your pool" seminar told us that antifreeze is heavier than water so pouring that in the main drain is useless. I guess I'll have to test this..
 

Hotrod30

Platinum Supporter
LifeTime Supporter
Dec 22, 2007
504
Central New York
Well, I looked up the specific gravity of Propylene Glycol; it is 1.038. Won't float. All these years I always thought it would float. All these years I knew it would float. :hammer:


O'well, I ain't asking about Santa.