Antifreeze in Skimmer


Jun 6, 2017
hartford, ct
Previously, I had my pool professionally closed. I'm in CT, so we definitely get a hard freeze here in the winter. I noticed that they would winterize the skimmers by plugging the hole to the filter, filling the skimmer with antifreeze and then put a 2/3 empty antifreeze jug upside down in the skimmer. Since it was professionally closed, I never bothered to look back in the skimmer after they left.

Fast forward to this year. I closed the pool myself and did the same thing to winterize the skimmers. About a week or two later, I decided to look in the skimmers and the antifreeze was gone...only clear water. We got a ton of rain, so the water level came up and into the skimmer (I let this happen every year). I thought maybe the plug was leaking a little so I drained things down, tightened the plug and refilled with antifreeze. Checked a few days later, antifreeze was still there and had not dropped. However, last night we get a ton of rain again, water comes into the skimmer, and this morning the antifreeze is gone.

So obviously the antifreeze is getting diluted and washed out when it rains and the water comes into the skimmer. My question is whether the antifreeze is even necessary? I know the professional did it previously, but I wonder if it all just washed out before the freeze happened anyways. Would a 2/3 empty bottle in the skimmer work to prevent the frozen water from cracking the skimmer plastic?