Seachem MultiTest Ammonia

Seachem MultiTest Ammonia measures both free and total ammonia in freshwater and marine aquariums, with 75 tests in the box. Ammonia is the first thing to spike in a new or overfed tank and the fastest way to lose fish, so a reliable ammonia test is one of the most important tools a keeper owns. It works alongside the rest of our water testing gear and water care.

Free vs Total Ammonia

Most kits only report total ammonia, but this one measures both, which tells you far more about what is actually happening in your water.

• Free ammonia (NH₃) is the genuinely toxic form that burns gills. How much of your ammonia is in this form depends on pH and temperature.
• Total ammonia is the free plus the much less harmful bound ammonium (NH₄⁺).
• Seeing both is especially useful when you dose a conditioner. A detoxifier locks ammonia into the bound form, so total stays up for a while but free drops, and this kit lets you watch that happen instead of panicking over a total-only reading.

When to Test

• Daily while a new tank is cycling, until ammonia rises and then falls back to zero.
• After adding new fish, a big feeding, or losing livestock.
• Any time fish look stressed, gasp at the surface, or a filter has been disturbed.
• As a routine check on any established tank.

Specifications

Recommended Pairings

• Seachem Prime, detoxify ammonia and nitrite instantly when your test shows a spike.
• Seachem Stability, build and hold the biofilter that keeps ammonia at zero.
• Seachem Ammonia Alert, add a continuous in-tank monitor so you catch free ammonia between tests.
• Seachem MultiTest Marine Basic, cover ammonia alongside pH, alkalinity, nitrite, and nitrate in a saltwater tank.

FAQ

What is the difference between free and total ammonia?
Free ammonia is the toxic form that harms fish, while total ammonia also includes the bound, far less harmful ammonium. This kit reads both, so you know how much of your ammonia actually matters.

What reading should I aim for?
Zero in a cycled tank. Any measurable free ammonia calls for a water change and a dose of detoxifier.

Will my water conditioner change the reading?
A detoxifier drops free ammonia while total stays elevated for a while. That is normal and is exactly the kind of detail a free-and-total kit is built to show.

Does it work in saltwater?
Yes, this kit is accurate in both freshwater and marine aquariums.