Do Chemicals to Test Fresh Water Fish Tanks Go Bad?

Theoretically, all aquariums should have their water tested regularly. However, most aquarium water tests have chemical reagents that expire and begin to produce inaccurate results within the year. Because of this, you must know exactly what test kits you need to use for your aquarium, so you do not waste money on test kits for parameters you do not need to worry about. On top of this, a few test kits can be replaced with physical equipment that does not expire. Knowing your test kits can save time and money.

  1. Shelf Life

    • Most aquarium test reagents have a short shelf life. Liquid reagents tend to expire in 6 to 9 months. Test strips can last longer, but ambient humidity can damage them in about the same time frame. Since you may need to replace your test kits, it is important to know which ones you should use. Additionally, some water parameters, like salinity and pH, can be measured with reusable equipment instead of test kits.

    Freshwater Basics

    • For most freshwater aquariums, you only need to measure ammonia, nitrite and pH. When you are cycling the aquarium, which is the process of establishing beneficial colonies of bacteria in the substrate that break down aquarium waste, you must test the water for these parameters weekly. Once the aquarium becomes established, you can test monthly. For pH, use an electronic pH probe instead of test kits. These probes costs more, but don't get used up like test strips or reagents.

    Advanced Freshwater

    • Some freshwater aquariums require other chemical parameters to be monitored. For example, some really delicate species require you to control the carbonate hardness. This is a measurement of dissolved minerals in the water. The specific value you want to shoot for will vary based on the exact species of fish you keep. Additionally, if you want to keep most aquarium plants, you also will need to measure the amount of carbon dioxide dissolved in aquarium water.

    Salt Water

    • For a fish-only marine aquarium, you still must monitor ammonia, nitrite and pH. However, you also will have to monitor nitrate levels with a test kit. Additionally, you must measure the salinity, which is the amount of salt in the water. To measure this, you will need a hydrometer, a tool that measures the specific gravity of the water. A hydrometers is a physical tool that does not expire, but it can break or wear out.

    Reef Aquariums

    • Reef aquariums arguably are the most complex aquariums you can have. To keep such an aquarium happy and healthy, you will need all of the test kits for a fish-only setup, and then some. To keep a reef tank healthy, you must monitor specific gravity, pH, alkalinity, calcium ion levels, nitrite, nitrate and ammonia weekly when you're adding fish and invertebrates. Once the aquarium is set up, you only have to test monthly. All of these reagents, other than specific gravity and pH, have limited shelf lives of up to nine months.