Nitrite is an intermediate metabolite in the CYCLE. Nitrite binds fish Red Blood Cells causing gasping and brown blood disease. Fish that die with their gills widely flared died of Nitrite induced "met-hemoglobin-emia"

Ways to combat nitrite intoxications are as follows:

* 1) Know the problem exists, a simple test will tell.

* 2) Partial waterchanges will lower Nitrite levels

* 3) Addition of salt (non iodized 1 teaspoon per gallon all at once) will inhibit uptake of Nitrites. (Preferred)

* 4) Methylene Blue at bottle doses will also help, but not entirely reverse the Met-Hemoglobin-emia.

* In many instances, the filter needs cleaning or upgrading.

* Feeding should be suspended or reduced.