The un-ionized ammonia calculator is an invaluable resource for on the go aquaculture producers and managers as well as home aquarium hobbyists. Ammonia is the major end product in the breakdown of proteins in fish. Total ammonia nitrogen (TAN) is composed of toxic (un-ionized) ammonia (NH3) and nontoxic (ionized) ammonia (NH+ 4). Over time the buildup of ammonia within the fish system, combined changes in pH and temperature causes fluctuations in the concentration of toxic un-ionized ammonia. AmmoniaCalc allows the user to input simple, easily measured water chemistry measurements such as pH and temperature to instantly calculate the un-ionized ammonia concentration.