Water changes. Nitrites during cycling should never be allowed to get over 0.25ppm and that is the edge of safety. NaCl will also help fish survive the toxic effects of nitrite at 1 tsp per gallon of water. But water changes are best.
My quarantine tank is also taking FOREVER to cycle, and that is with BioSpira added. I am about to add material from one of my other filters, because this has been going on over a month. Fortunately I am doing it fishless, so it isn't a huge problem, but I really want to get some fish in quarantine.
thats the thing i have done water changed. i even did a 50 percent water change and it didnt change. could there possibly be something building up in the filter or something. i will continue to do water changes though