Hi,
There's no real simple way to get rid of nitrite, except for bacterial processing it into nitrate or water changes. This is done by bacteria on your LR and DSB. Ammonium & nitrate can be processed directly by macro and other algea types.
From all my reading nitrite needs to be processed to nitrate by bacteria.
There's some real debate going on about the types of bacteria that are actually doing the work. Some new theories say that one type of bacteria can become nitrogen fixing in the prescence of oxygen and then switch to denitrifing in the absents of oxygen. Search the net for "
Nitrogen Cycle" for more info. (forgive my spelling

)