To use the EnviroCool Cleaner Filter , you must test the coolant first for inhibitor and antifreeze levels (a test kit is included in the filter package.) If the inhibitor or antifreeze level is not satisfactory, liquid make-up such as Nalcool 2000, Cool-tech, or Fleetguard DCA is necessary to bring the level up. EnviroCool has included in its formulation film formers, anti-foams, pH buffers, as well as concentrated chelant cleaners. These protective chemicals, such as nitrates (for aluminum protection), Tolytriazole (TT, for red metals), borate buffers (to maintain alkaline pH), and Pluronic L-61 anti-foams (to stop cavitation corrosion) are effective as evidenced by the independently conducted ASTM series of tests.