back to the glycol thing I happen to know for a fact that all antifreeze breaks down over time. the next time you buy some cryo-tek ask the supply house for some test strips , on these test strips there are 2 pads 1 for concentration 1 corrosion , every manufacturer will have there own strips but they are for the most part interchangable. What I will admit and have in the past in 0 experience with water source but Ill take the pepsi challenge with the hydronic service and install history with anyone

Trion Air Bear filters are, I believe, MERV 8. The water comment was a bad joke, re antifreeze choices; vertical closed loops are not wells and will not effect water. Accidental spills, like any spills, may have an impact, but properly fused pipe will last indefinately.
j

MERV is a rating of a filter's effectiveness at filtering tiny particles. The higher the MERV, the more it filters from the air.