Another good question, Mike, and one that Mother Nature had provided a solution for.
Ammonia (very harmful) and Ammonium (not nearly as harmful) exist in a ratio that shifts based on pH and temperature.
At lower pH, and at lower temperatures, the relationship shifts to a higher percentage of the safer ammonium and less of the more dangerous ammonia -- thereby protecting your fish when the bio-bugs are down. No binder should be necessary
unless there's something like dead fish or large amounts of decaying plant/algae material in your pond, in which case getting rid of the cause is the best solution.
Anyway, that's my layman's explanation. Someone with a solid grounding in chemistry (like Roark, Roddy or Rick F) would do a much better job of explaining this, I'm sure.
