Keep your aquarium water in check with our Water Parameter Magnet. This handy tool displays the ideal ranges for pH, temperature, nitrate, nitrite, and ammonia levels, making it easy to ensure your marine fish live in a healthy environment. The magnet can be placed on the outside of your aquarium, or where ever you do the most testing, and is waterproof, ensuring it stays in place and won't get damaged from exposure to water. Use this magnet as a quick reference guide to maintain optimal water conditions for your marine fish.