Ammonia is one of the bigger problems you can run into in aquaponics, but with the proper procedures, your farm will be back up to speed in no time.
Why Ammonia is a Problem
In a perfect world, aquaponics would never result in an over-abundance of ammonia in the fish task, as the noxious chemical is siphoned out of the water by the plants. However, if your balance of plant life and fish isn't quite right, ammonia could become a problem, eventually posing a health hazard for the fish.
How to Test
Purchase an ammonia test kit that uses strips that you insert into the water. Some kits for conventional aquariums use liquid or powder that you drop into the water; this is not appropriate for an aquaponic tank as these contaminants will end up in your garden. Insert the strip into the water and leave in place for about five minutes. Check the color of the strip against the guide provided by the manufactuerer and you know know if you tank it overwhelmed with ammonia.
What to Do If Your Tank Tests Positive
Replace the water in your tank with a clean batch. Consider decreasing your number of fish or increasing your number of plants to ensure that the ammonia the fish produce is absorbed by the plant life.