[dtoguin]

I have a 46 gal. tank that constantly tests 1ppm of nitrites. Everything else is normal. We have done water changes twice 20% & 25% in last 2 wks. still has the nitrites. We have removed some of the rocks in the tank that came out of the backyard. ( boiled them for 15 mins.) We had the tank set up for about 3 wks before this problem started. Does anyone know what it could be. We do not have any sick fish from the level of nitrites.

[watrsedg]

Water naturally contains less than 1 milligram (1ppm) of nitrate-nitrogen per liter, it comes from nitrogen and oxygen. because that amount occurs naturally, i doubt you will be able to remove it It shouldnt cause a concern since drinking water can contain 10 ppm and still be considered safe to drink