API Ammonia Test Kit is a simple to use kit for determining dangerous ammonia levels fresh and saltwater aquariums. It is a liquid type of kit which works by changing the colour of a water sample in relation to the ammonia concentration. You simply need to compare the colour of the sample to the easy-to-read colour chart to determine the ammonia level. Always read the instructions carefully before use. Suitable for up to 130 tests. Includes 2 test solutions, easy-to-read instructions, test tube and 2 colour charts.