Young Macdonald's Farm Nitrite Nitrite is the product of the biofilter resulting from the breakdown of ammonia. Converting nitrite to nitrate seems to be the least dependable part of the nitrification process. It seems to be easily upset by rapid changes of nearly any kind, also these bacteria seem to be easily dislodged, so swings in nitrite levels are common. Nitrites are toxic because inhibit the hemoglobin of the fish from absorbing from the water, therefore even though oxygen tests indicate DO is in good supply, if the fish are exposed to high nitrite levels they are still oxygen starved resulting in poor growth and poor generally health. Fortunately, nitrite levels toxicity can be contracted by the by the addition of chlorides (NaC!) at the rate of 6 ppm chloride for each 1 ppm of nitrite (example: if nitrite values are 3 ppm ­ maintaining 18 ppm- of chlorides controls the problem). It may be good practice to routinely maintain chlorides at 100 to 150 ppm in your system at all times. It not only reduces the threat of nitrite toxicity, but also relieves stress, reduces fungus infections and reduces the energy required by the fish to perform active transport of materials across cell membranes. In testing chlorides if you use a Hach test kit your supply of nitration material will be quickly exhausted if you test levels of 150 ppm chlorides very often ­ so dilute with distilled water before testing ­ with the Hatch test measuring tube for chloride has a volume of 6 mi. they also supply a dropper that measures .5 ml. So simply place .5 ml from your system in the measuring tube, fill the tube to the top with distilled water and test as directions indicate. When finished multiply by 12 for total result. This reduces the amount of test materials required to measure relatively high chlorides. Variations of the same methods can be used for ammonia and nitrites that test higher than the scales in the same kit allow you to read. Just remember to multiply by the rate of dilution to obtain a final reading. NOTE: SEE - Remote water quality management