nitrite

[LMOUTHBASS]

ok so the good bacteria eats the amonia which then turns to nitrite, but how do you get the nitrite to turn to nitrate???? this is what you eventually want right???

[JSchmidt]

Bacteria also consume the nitrite and produce nitrate as a result. It seems to be a different species of bacteria from those that consume the ammonia.

Nitrate is significantly less toxic than either ammonia or nitrite. It's not good for the fish, though, so we generally use water changes to keep nitrates below 40 ppm (some prefer to keep them lower than that).

HTH,
Jim