I did not realize it was this high. I was busy doing some substrate maintanance on one of my tanks. This tank is a medium light (2.5 wpg) CO2 injected tank substituted with Seachem's Flourish weekly with a 50% waterchange. Tank size is 29 gallons. The tank has 2 vallisneria plants, an amazon sword, lots of anacharis (20-30 stalks) and a bannana plant. A while ago I posted a photo of the tank. The plants were removed for 12 hours and the ammonia test went from 0.0 to slightly over 1.0 in that timeframe. That sort of ammonia consumption is incredible (About 2.2 ppm per 24 hours). It just shows you how lacking biofiltration is in a planted tank. The plants have been re-added and I did a big waterchange to bring ammonia back to safe levels. I am sure ammonia will test 0 by tonight. Just sharing this interesting tidbit of information.