My tank is now about 5-6 weeks old. It's a 10 gallon tank with only 2 little neon tetras in it. I put Biospira in the tank about a week and a half ago. The nitrites are at zero, the nitrates are between 5 and 10, but the ammonia is back up to 1 ppm from about .5. I changed the carbon 3 days ago. What am I doing wrong? Why would the ammonia still be so high? I was away for 2 and a half days and left some of that gel pack weekend food in there which I don't think they even touched. Could the food have spiked the ammonia? I just don't know what to try anymore. Shouldn't the bacteria be doing it's thing by now?