Using the Tetra Oxygen Test Kit will help you to accurately pinpoint the level of oxygen in your aquarium. Renowned for their aquatic expertise, this test is designed for the optimum performance.Oxygen is an essential element for all living beings including those in your aquarium. So fish, plants and any other organisms all need it for respiration. Plants need oxygen in order for photosynthesis to occur, so levels must be monitored for a healthy tank.If oxygen levels fall, this can cause stress to fish and leave them to susceptible to disease and also cause biological filtration media to stop working sufficiently. Plants will also wilt and possibly die, if levels fall to low.Testing weekly with this efficient kit will mean that you can always make sure that your aquarium is perfectly healthy. Everything you need is included in the kit, simply compare your results to the accurate colour chart.Oxygen levels are affected by:Temperature, especially if rises to over 80⁰FOverstocking fish leading to high waste matterPoor circulationSurface filmsKey Features:2 x 9ml test reagentsTest vialColour ScaleInstructionsEnough to carry out 30 testsSuitable for all freshwater and marine aquarium