Master the chemical processes that keep your aquarium fish healthy and thriving, from the nitrogen cycle to pH management and water hardness.
NH3 (un-ionized) / NH4+ (ionized) — Inorganic nitrogenous compound
Ammonia (NH3/NH4+) is the most toxic compound in the aquarium nitrogen cycle, produced by fish waste and decaying organic matter, and safe only at a reading of 0 ppm.
NO2- — Inorganic nitrogen ion, second stage of the nitrogen cycle
Nitrite (NO2-) is the second, often more persistent, toxic stage of the aquarium nitrogen cycle, causing 'brown blood disease' by blocking oxygen transport in fish.
pH = -log10[H+] — Measurement of hydrogen ion concentration (logarithmic scale, 0-14)
pH measures how acidic or alkaline aquarium water is on a 0-14 scale; stability and its effect on ammonia toxicity matter more than hitting one 'ideal' number.
