Ammonia testing methods

Hi everyone,

I know that certain water conditioners can cause Nessler method Ammonia Test Kits to produce false readings and that there are also Salicylate method kits available which can measure Ammonia, but is there any other reason to prefer one type of kit over the other? Do both methods produce equally accurate results in freshwater which has not been treated with one of these conditioners? LaMotte's information states that the Salicylate method is preferred for Saltwater but can it be used in Freshwater as well?

A curious mind would like to know... (one whose memory of analytical chemistry is fading fast).

James Purchase
Toronto, Ontario
jpp at inforamp_net