I got a new 75G aquarium for my birthday back in July, and I set it up back in the beginning of August, and it is currently going through a fishless cycle. I started with about 15ml of Ammonia which brought it up to 4ppm. It only took a week and a half for the bacteria to form to process the ammonia into nitrites, and I can now add about 10ml of ammonia, and it will be 0ppm within 24hrs... Great!
The problem I am having is with the nitrites. It has been high ever since, and hasn't showed any signs of going down, even though I was showing high nitrate levels. I don't remember the exact ppm number for the nitrites, since I don't have the kit in front of me, but it's the second to last color on the API fluid kit... A very dark purple. My nitrates were showing about 80-100ppm, so I did a 80-90% water change, which brough them down to about 5ppm, but nitrites are unchanged.
I checked my tap water to make sure nitrates / nitrites weren't present, and they all showed 0ppm.
I'm not sure what's going on... I'm starting to get impatient... lol.
Oh yeah, I forgot to mention that I did seed my new tank from my current 10gal tank which has been setup for about 1.5 years. I've tried seeding with gravel in a nylon bag, floating an old filter cartridge, and I even put some of the decorations from the old tank into the new.
Please help me, I'm not sure what to do.