Meaning to say - I mixed up a batch of Tergitol a couple of months ago in anticipation of the upcoming purchase of a bunch of records. Time kind of delayed that, and between then and now I've only been able to clean about 12 records. Not enough to cause any weird growths to develop in the tank (indeed, it looks as fresh as when I made it), but is there any risk to losing the concentration of the Tergitol over so long a time? I'm wondering if I should dump it and start over since there's no way to measure the concentration. The tank has been covered when not in use.