Pool Antifreeze...What's The Point?

[Tomolena]

A number or people on this board pour antifreeze to protect their lines during the winter freeze. I've read recently that antifreeze is heavier than water, So it would naturally sink to the lowest point in your plumbing. If that point is below the freeze depth, then there there doesn't seem to be any benefit. That would be especially true for those people who like to pour antifreeze into their main drain line. My main drain is eight feet down. The water doesn't freeze at that depth.

I took some pictures when I had my pool renovated in April. In the picture below, you'll see one of the skimmer lines running behind the pool light. The line, at that point, appears to be 18 to 20 inches down. Since lowering the water below the top edge of the light is not recommended, what's the point to adding antifreeze? Am I missing something here?

 

[Chemnut]

If you are 100% sure all the water is out of your lines it's not needed, however, it's a great back up. Do you know how deep the frost line is for your area?

 

[Tomolena]

Not sure how to determine that. A cursory search comes up with frost line numbers from 18 to 36 inches. I might be wrong, but I'm guessing that elevation would also be a factor. Hicksville is, on average, 148 feet above sea level.

I close myself using a Cyclone blower and I'm very confident that my pipes are dry when I finish. But I am a big fan of "back ups." That is why I used antifreeze last year. I'm starting to wonder if the only one who benefits is the guy who sold me the antifreeze.

 

[Chemnut]

More than likely, but it's a very small price to pay just in case...

 

[Catanzaro]

I do not believe in antifreeze. If the lines are cleared out properly, then no need. But again, all a comfort issue. The skimmers are bone dry by the time I am done with them as the water is lowered 2" below the skimmer and I vacuum water out while using the Cyclone. The return jets should have about 2" of water left when all said and done. The main drain is another issue, but if the pump is at a higher elevation, I honestly to do believe the water will siphon back in the event air leaks out of the plumbing.

 

[Chemnut]

Not a gamble this northerner is willing to take. 1 gallon is $4

 

[Catanzaro]

I did see RV antifreeze that can be used for pools at Lowes yesterday for $5. That is not a bad deal. There was a post during the season about antifreeze being used and consuming extra chlorine for quite a while, or almost double until it disappeared.

 

[Mkleisch]

During startup next year, do I need to remove the Antifreeze or can I let some mix with the pool water?

 

[Tomolena]

You can let it mix. Pool antifreeze breaks down fairly rapidly once you get your plumbing going. No harmful byproducts left over.

 

[Catanzaro]

If you do not need antifreeze, then do not use it. Here at TFP, we teach not to add chemicals that are not needed. There was a post a few months ago during the opening of a pool, and the chlorine consumption was double. This could have been because of antifreeze. If the lines are cleared out properly, then I see no need. This is all a comfort point for pool owners.

 

[pookiesunshine]

If you do use antifreeze, you might consider flushing the lines to waste instead of back into the pool at startup.

 

[Mkleisch]

Sounds good. I'm in Chicago so it freezes pretty hard here

 

[Chemnut]

RV Antifreeze is and should be used by anyone closing a pool in northern climes to prevent damage. 2 gallons will more than suffice. It will have no effect on balancing come spring time. I don't see it as an unnecessary chemical addition. Pools in my area will see such a deep freeze that there is often 4' of ice in a deep end.

flushing to waste won't work for the return lines.

 

[Catanzaro]

there is often 4' of ice in a deep end.

Yes, in this case, antifreeze should be used. My worst ice is 1" on surface of water.

- - - Updated - - -

I don't see it as an unnecessary chemical addition.

I mentioned that if antifreeze is not needed, then do not use it. In climates where ice freezes 4', then clearly this is necessary and needed.

- - - Updated - - -

Tomolena:

I was just looking at your picture and see that plumbing is only about 1' deep. Now I understand your situation. My plumbing is 3' down and encase in concrete all around the pool. Only piping out of the concrete is on the way up to the skimmers and returns. Then the remainder is about 3' from deep end and gradually at higher depths on the way up to the equipment pad. The pad is 5' higher then pool, so gravity is on my side. If you ask me, all the plumbing in a swimming pool should be encased in concrete and designed for northern climates.

 

[pookiesunshine]

....

flushing to waste won't work for the return lines.

When i said waste, i meant not to the pool, not literally the MPV waste setting. I have elbows with capped extensions to close my return line jet openings. these can be turned up at spring opening so that the extension opening will be above water level when uncapped. the other thing to do is open the return line somewhere downstream of the filter outlet. i have a union in the return line that lets me do that. I then blow out the return lines backward from the jet openings to the opened line near the filter outlet. overkill? maybe. but minimal effort for me.

 

[PoolguyinCT]

I like antifreeze because it is visible, particularly in complicated piping or Large piping we have some 10" systems. I like antifreeze because I can see that I have coated the entire piping path when it exits the other end of the pipe. So to me it is chiefly a visual aid for elaborate or giant systems.

 

[Marty D]

I use antifreeze in the skimmer because even if you get all the water out and plug it. When it rains water comes through the winter cover and water will sit in the skimmer. Put antifreeze in the skimmer.

 

[Tomolena]

re: "I was just looking at your picture and see that plumbing is only about 1' deep."

Perhaps the photo is deceptive. I was standing right over the trench when I took the shot. That flex-pipe is a minimum of 20 inches below the metal surrounding the pool.

 

[dandigger]

Second year inground pool owner here, first year closing myself.
Can I get a confirmation if this very brief step by step for adding antifreeze is accurate??

-Drop water below skimmer inlet
-Blow out lines
-Remove eyeball jets, insert caps/close off
-Add antifreeze to skimmer until full (??)

I guess my questions is 'Do I just only add antifreeze from the skimmer to the pump/filter (disconnected), or do I also add it from the pump/filter to the outlet jets that are now closed off??

 

[Catanzaro]

Add antifreeze to skimmer until full (??)

If you remove the water from the lines, no need to add all that antifreeze until full. You will go through a lot of gallons. Antifreeze is good to use if you have water in the lines (a lot of water). If you have little to no water as you cleared the lines properly, then either no antifreeze or very little antifreeze is needed.