Ok so how did alcohol backtrack into the pump, or was that a different pump that got alcohol backtracking?

Do you know how condensation gets in the lines or what the solution is? Is the windmill line somehow more prone to condensation build up due to lower PSI than the ones that are run by the bigger solar powered pumps? It seems you could keep moving condensation through the lines with the PSI (40) that you are pushing through those lines compared to most aeration systems that are say 10 or less psi.

And if condensation happens and you freeze up does that happen only in the section where the air line is under dirt on the way to the water, or does that happen in the area where it is on the bottom of the pond/lake? I would think the warm water on the bottom of the pond would keep things from freezing up there.

I'm showing my ignorance here but probably others will face condensation at some point and this is a good time to understand how it happens, why it happens, and how to fix it.