API Ammonia Test Strips, 25 Count

API Ammonia Test Strips are a single-parameter test for ammonia in freshwater and saltwater aquariums. Each box contains 25 strips (model 33D). Dip a strip in tank water and compare colors to read the result.

Why ammonia matters most

Ammonia is the first toxin to build up in a new tank and the one that kills fish fastest. It comes from fish waste, uneaten food and decaying matter. Even low levels stress fish and damage gills. A dedicated ammonia test is the most useful single test a new keeper can own.

When to test

API suggests testing several times a week when starting a new aquarium, then weekly or whenever problems arise. Good moments to test:

• Daily during the first weeks of a new tank
• After adding new fish
• If fish gasp at the surface or seem lethargic
• After a filter has stopped or been cleaned hard

What to do if ammonia shows

1. Do a partial water change with conditioned water.
2. Cut feeding for a day or two.
3. Check that the filter is running and not clogged.
4. Consider a bacteria starter like API Quick Start.

A conditioner that binds ammonia, such as Seachem Prime, can protect fish while the biofilter catches up.

Strips versus liquid

Strips are quick and need no tubes or drops. For finer readings at low levels, the liquid ammonia test in the API Freshwater Master Test Kit is more precise.

Handling tips

Use dry hands, close the box after each use, and store it in a dry cupboard rather than the humid cabinet under the tank. Read at the time stated on the box in good light.

Who it suits

New tank owners and anyone who wants a fast ammonia check between full test sessions.

Remember that a strip only shows the moment you test. Ammonia often peaks a few hours after feeding, so testing at a consistent time of day gives you comparable readings.