Check the nitrate/nitrite levels in your pool if you are seeing excess chlorine demand. A positive nitrate test indicates a potential for algae growth. Dip and read test strips give results for both in less than one minute. AquaChek Nitrate/ Nitrite test strips makes it easy to test, monitor and control the levels of Nitrite and Nitrate in swimming pool water. 25 Nitrate test strips per bottle. AquaChek Nitrate/ Nitrite Test Strips test for: Nitrate Nitrite Includes 25 test strips.