Ammonia poisoning

Ammonia poisoning is a common fish disease in new aquariums, especially when immediately stocked to full capacity.

Species of ammonia-oxidizing bacteria (AOB) can break down the ammonia and convert it to other, less toxic, nitrogen products.

A history of the tank, such as filter changes, power outages, excessive feeding, or the addition of microbicidal or antibiotic agents to aquarium can aid in diagnosis.

Ammonia affects fish metabolism and their ability to absorb oxygen through their gills.

This leads to a host of symptoms a few of which are: Ammonia poisoning can be prevented easily by first cycling the tank (see below).

Schematic representation of the flow of Nitrogen through a common aquarium.
The nitrogen cycle in an aquarium.