200 Gallon Cycle Stalled at Nitrite Phase

[Reluctant Pirate]

Hello all. I'm new to this site, but not exactly new to the hobby. I recently acquired a couple of fish under emergency circumstances, so I had to set up a tank very quickly. I have a 200 gallon tank with wet/dry sump filter setup, and I'm trying to cycle it with these fish in the tank.

The problem I have is that the cycle seems to have stalled. Ammonia levels have dropped to less than .25 ppm and have stayed there consistently for about a month. Nitrite levels are consistently over 5 ppm, and I've been using Prime to keep the fish alive. Of course, Prime makes the water test at 0 ppm nitrite for awhile, but it always returns to 5+ within 5-6 hours. Daily testing has never shown any nitrate at all.

Water changes are wholly ineffective at reducing the Nitrite levels, as they return to 5+ within hours of even the most drastic water changes (80%+).

I've tried using Stability for a couple of weeks, but it has had no effect.

Any ideas?

 

[Demeter32]

The best thing to do is find someone who has a cycled tank and steal some of their seasoned media then add it to your filter box w/o rinsing it or anything. Seeding a tank is the fastest and most effective way to cycle it.

 

[Reluctant Pirate]

Yeah, I wish that were an option. I know no one with an aquarium.