Aqua Logic Chiller Leaking?

[rnsmith]

I have a nine year old Aqua Logic 1/3 hp chiller which I am using on a 100 gallon system. Last fall it seemed to be loosing effectiveness. This spring I had a refrigeration repair guy look at it. While checking the refrigerant pressure with the gages, - while the unit was running - the needles would occasionally fluctuate. He suspected that was due to “water” being in the refrigerant â€"œ which seemed odd. He took the system to his shop and changed the “dryer” module in the refrigerant line and recharged the system. Meanwhile, I called Aqua Logic and asked them what the chances were that water was getting into the system though the coil located inside the exchanger unit. (That is the only point when water contacts the plumbing containing refrigerant.) He said that such seemed “odd” that the coil in the exchanger would be leaking, and that I would be noticing an oil sheen on top of my water surface if such was the case â€"œ from the oil in the refrigerant escaping with the gas. Now that the chiller has been back on line for two weeks, it seems to be, for the time being, working fine. BUT, I do notice that the protein skimmer tends to be running kind of “flat” â€"œ like right after I add Selcon or fatty substances to the water. I do not see any “sheen” of oil on top of my water. Would anyone have any ideas as to how I would know if the chiller coolant or oil is leaking into the water??