Had my thinking cap back on for this project.
Considering my local weather
https://weatherspark.com/averages/31...-United-States
I have several days that are going to be warmer than the pond while I am heating. Example, today it got to 56F, so my unit would be running more efficient running air source than it would be pond source (42F) today. This isn't uncommon either.
SO should I tie in the air source coils and have it on a solenoid on days like, so it can use the warmer air? It would be a design nightmare so the next question would be is it worth it? lol