Hi, I bought a house with an existing loop. No problems thus far. Have topped off the pressure with a gooser but would now like to confirm there is adequate antifreeze but I can't tell if they used PG or Methanol as the fluid is colorless, tasteless, no smell. I know there IS antifreeze because I've had the house a few years through cold spells without a problem. So, I did the freezer test, the outcome of which I thought might tip the right person off: Put a small amount in a cup in the freezer with a thermometer to see when it started to freeze. The fluid started to gel but not freeze in the 20s (it didn't start to freeze until about 15). Thought the fact that the fluid gel'd long before freezing might allow a seasoned person as to the likelyhood of PG vs Methanol (can't be calcium because the Geo-flow center doesn't allow it). Thanks for any thoughts!