ChangeWater Check water quality test strips give you the ability to know when a water change is needed in your Aquarium or Pond. Designed with the aquarist in mind, ChangeWater Check test strips are fast and easy to use, with no wet or hazardous chemicals. Just dip the strip directly into your aquarium or pond and then match to the color chart. Ideal for the beginning aquarist, this test yields accuracy and reliability that an expert can count on. ChangeWater Check test strips give you an indication of your Nitrate and Nitrite concentrations which can build up in your aquarium or pond due to uneaten food, waste, bacteria, and ammonia presence.