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    There are a number of ways to test for NH3 and NH4 in the aquarium, probes and dip strips are still uncommon and most people use liquid test kits. These occur in two main types liquid ammonia test kits:


    Nessler kits have one reagent, that is, a single bottle of liquid or one tablet to dissolve in your water sample. If your ammonia test kit registers in shades of amber, it's Nessler. They generally are quicker to use, but ammonia-locking products (e.g., AmQuel) will cause Nessler kits to give false positive readings. Nessler test kits measure ammonia NH3 and ammonium NH4. This is important to note and often missed.


    New Salicylate based tests, with two sets of reagents measure NH3. If your ammonia test kit registers in shades of yellow to green to blue, its salicylate. Salicylate test kits are unaffected by AmQuel and similar products, but they do take longer to develop a reading and are more complicated to use correctly which can affect accuracy.



    Testing for ammonia with the test kits above might produce false readings after a water change if you add to much de chlorinator. Seachem's Prime conditioner will give false readings for ammonia, on both Nessler's Reagent and salicylate tests. Sodium thiosulfate, Na2S2O3, in Prime reacts with the chloride ion that is part in the test reagents. According to Seachem after 24 hours you will then be able to test again and get accurate readings.


    An alternative is to use a seneye device which will constantly measure the toxic ammonia in your aquarium or pond.


    If you have high ammonia then this link will help...