Removing Anti-Freeze from Skimmer and Return Lines


Well-known member
May 22, 2018
Elmhurst, IL
Discovered TFP during a very stressful pool opening last year and found the information and help here absolutely amazing. Looking forward to a less stressful opening this year. Will start SLAM process in a couple of weeks.

Quick question: How careful should I be about keeping anti-freeze (added to skimmer and return lines when closing last winter) out of the pool and what is the best method to get rid of it? Should I try to vacuum most of it out at the skimmer and return line (only have one of each) and then start the pump with the multi-port valve set to Waste before I start filtering? Any concern if some of the anti-freeze gets in the pool water?


Gold Supporter
TFP Guide
Jul 21, 2013
Northern NJ
Just let the antifreeze mix with the pool water on start up. The small amount will get diluted and not harm your water chemistry.


Gold Supporter
TFP Guide
Jul 21, 2013
Northern NJ
Thanks for the prompt reply. There's about 10 gallons of anti-freeze in the lines..... sure all that in the pool won't cause any issues? Thanks.
There are 20,000 gallons of water in your pool. That's 10/20000 dilution. It will be consumed by your chlorine.

Was it pool or RV antifreeze?


TFP Expert
LifeTime Supporter
Jan 6, 2010
San Dimas, CA (LA County)
Got a wet-n-dry shop vacuum? Pull plugs and suck the lines to remove antifreeze. Then connect everything and fire it up.

In years past some people ended up with a lot of CC trying to oxidize all the leftover antifreeze. If I lived somewhere that it freezes, I'd want to remove as much from the lines first.


Silver Supporter
May 29, 2018
Chicago, IL
I used about 5 gallons on mine at closing, i just let it back in the pool and it did not seem to hurt anything.
JP I relied back to your pm, we are going to have to make plans to have a beer and talk pool this summer.


Bronze Supporter
Aug 2, 2017
SE Kansas!
Thank you for your help. I will try to vacuum out most of the anti-freeze. I believe it was an RV type anti-freeze, but also suitable for pools.
As long as it was the non-toxic RV or Pool antifreeze, since you are planning to SLAM Process, there's no need to go to the extra work of removing, unless you are wanting too :)
Where were you planning to dump the removed antifreeze?


Apr 17, 2019
North East
I always just pump it out. I first hook up pump, pull plugs in returns and skimmers, put garden hose in pump basket, turn on to prime pump, turn multi valve to waste, turn on pump motor, look at back wash hose and all the red AF coming out. Done.
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Bronze Supporter
Apr 14, 2018
Cincinnati, Ohio
I tend to go overboard on simple protective measures to satiate my pool ocd when closing. I built this simple piece to screw into the Jets so I can blow most of the antifreeze out of the lines exactly like I did when I blew the water out when closing, yet keeping the antifreeze out of the pool water. A hose at the pad to refill the lines with water as I blow them out one at a time worked great.