in a well established tank is there a chance that you can ever see nitrites or ammonia in your tank again???? Like in FW basicly after teh cycle you never see it again unless you make a obvious change to the filtration or something. My 150 is about 5 weeks old, but it was started with 70 lbs of rock from my existing tank and all 65 gallons of matured water from that tank were all moved into the 150. Then the rest of the water added was new and I added 80lbs of live rock. I obvioulsy went through all the cycle again although my nitrites still won't go down. It won't even budge. Can over feeding, trapped debris, or anything else cause nitrite to rise????for some reason my tank just doesn't want to break down those nitrites. Would a cycling additive work something like seachem stability????