I have my pool "professionally" closed every year, but I open it myself in the spring. This year, I noticed that instead of using the Gizzmo, a standard plug was capping off the pipes in my skimmer. And, for some reason, an empty but capped bottle of pool antifreeze was sitting on top of the cap. Is there any rationale for not using the Gizzmo and capping off the system instead? (Last year, instead of using the Gizzmo, they put an empty antifreeze jug in the hole, upside-down.)