Now the trailers in my fleet were older but it appeared to me that the antifreeze soaked into the lines then when it got hot outside some would leach back into the water flow. Once the weather got hot it seemed like every time the trailer set for a couple days the water tasted like antifreeze and was also foamy coming out of the faucet. So about 10 years ago we stopped using antifreeze and just blew the lines which with 30 trailers made since anyway. I don't put antifreeze in my own trailer lines just for this reason. 30 trailers setting outside during harsh Utah winters and we never had a problem with freeze damage.