API Ammonia Test KitThe API Ammonia Test Kit measures ammonia — the number-one killer of aquarium fish. Ammonia enters the water constantly through fish waste, respiration, and decaying food, and even small amounts stress fish, suppress their immune systems, and can quickly turn fatal. This liquid test lets you track ammonia precisely, which is essential when cycling a new tank and reassuring on an established one (where it should always read zero).A salicylate-based liquid test, it's more accurate and longer-lasting than strips, with enough reagent for well over a hundred tests. It's the standalone choice if you specifically want to monitor ammonia, or a refill for the parameter most worth watching.Good to Know — the "Prime" surprise: API's liquid tests measure total ammonia. If you use a conditioner like Seachem Prime or Safe, it detoxifies ammonia without destroying it — so the test will still show ammonia present even though it's in a harmless, locked-up form. A non-zero reading right after dosing Prime is expected and usually not cause for alarm; your biofilter will consume it over the next day or two.How to Use: Fill the tube to the line with tank water, add the drops from both ammonia reagent bottles as directed, cap and shake, wait the stated time, and match to the color card. Test every day or two while a tank is cycling, then weekly once established. A reading above zero on an established tank points to overfeeding, overstocking, or a struggling biofilter.
