Nitrite in Koi pond

The aerobic oxidation of ammonia in water by chemoautrophic bacteria produces nitrite.
High levels of nitrite in water will be absorbed by the fish's gills. In the blood, it oxidizes the iron on hemoglobin producing methemoglobin that prevents the red blood cells from carying oxygen. Methemoglobinemia causes the blood and gills to turn brown. Death in the fish occurs from hypoxia. Toxic conditions occur when the nitrite level is above 0.10 mg/L in soft water or 0.20 mg/L in hard water.
Some kits used fro water analysis test for nitrite-oxigen, rather than total nitrite. With these test kits, multiply the nitrite-nitrogen value 9in mg/L or PPM) by 3.3 to get the total value of nitrite present.

Treat nitrite toxicity by partial water changes, increasing the oxigen concentration in the water, increasing the aerobic biological filtration, and by adding salt to the water. The chloride ions from sodium chloride complete with nitrite ions for absorption by the gilld, reducing the toxicity. There should be 6mg/L of chloride ion present for every 1 mg/L of nitrite ion to prevent toxicity. Add salt at a rate of one teaspoon per gallon of water, or one pond per one hunderd gallons, to achieve 0.12%  salinity (1200mg/L). This dose is very safe for koi and enough to reduce nitrite toxicity. Salinity tests are available to monitor salt levels in pond water. Chloride test kits can also be used, with 1mg/L of chloride ion equivalent to 1.67 mg/L of sodium chloride.

Need help with your pond testing call Chuck 770 359 9927 for  a Consultation
or visit Splendor Koi and Pond and let us help you!