unexplained ammonia levels

[sinclair]

I've had a Percula Clownfish in a 50 gallon tank for about six months with no problems except for algea. A few days a ago I added a blue tang (yes the tank is for my kid) and things were going fine, the fish ignored each other most of the time. I also added a filter bag with a substance to reduce carbonate levels and algea on the advice of my local aqua store. Here is the problem. The clown seems to be gasping for air at the top of the tank. I did my monthly chemical check. PH, NO2, and CO2 perfect. But, the ammonia level is off the chart. Here is the strange thing...I only have two small fish, I don't overfeed, the water is crystal clear, there is no ammonia odor whatsoever. In years past I've overpopluated tanks and know the tell tell signs of ammonia without a test but the water looks perfect. Any clues? could it be the carbonate filter media effecting the test?

[scuba_steve]

welcome to aa ! my guess would be yes ! id remove it and see if things get better

[MarkLehr]

You may have purchased an actual ion exchange resin. If you have NH-4 ammonium in your system (which is non toxic and does not show on test kits), then should a Hydrogen ion be removed you would have NH-3 ammonia.

My memory of the chemistry behind this concept is very bad. But I do recall that this is possible and your new filter resin could be the problem.