Aquarium Water Testing
Water testing, part of regular aquarium maintenance, includes using a water test kit to ensure the water is non-toxic and has the proper elements.
For freshwater aquariums, the API freshwater master test kit is a great entry level option that includes a pH test kit, nitrite test, nitrate test kit, ammonia test, and general hardness test. With these tests and a thermometer, the freshwater basics are covered.
A basic saltwater test kit should include pH, nitrite, nitrate, and ammonia test kit. A good reef aquarium water test kit will also include an alkalinity test and a calcium test kit. A phosphate test kit, which measures available nutrients for nuisance algae, is also a good idea. The API reef master test kit is an excellent entry level choice.
The Red sea test kit or Salifert test kit series are popular hobbyist level kits. The Hanna Checker colorimeters offer digital water testing. ATI and Triton Labs offer lab-grade mail in testing.