Test Kits

API Nitrite Test Kit

Liquid testFreshwater & marine180 tests

The API Nitrite Test Kit reads the middle step of the nitrogen cycle. As bacteria break down ammonia they produce nitrite, which stops fish blood carrying oxygen: low levels suppress the immune system and high levels suffocate fish that are otherwise in clean-looking water. The single-reagent liquid test measures nitrite from 0 to 5 ppm in freshwater and saltwater, and the kit holds 180 tests, a glass test tube and a colour chart. It is the test that tells you a new tank is halfway through cycling — and whether it is safe to add more fish.

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Live pricing and stock on jungleaquatics.com — purchase through Jungle Aquatics, with delivery across South Africa.

Technical details

Test type	Liquid reagent
Parameters	Nitrite (NO2)
Range	0 – 5 ppm
Tests per kit	180
Suitable for	Freshwater and saltwater aquariums
In the box	1 reagent bottle, glass test tube, colour chart, instructions
Made by	Mars Fishcare, USA

Ammonia reads zero but nitrite is high — is the tank cycled?

Not yet — it is halfway. Zero ammonia with nitrite present means the first group of bacteria is working and the second group, which turns nitrite into nitrate, is still establishing. The tank is cycled only when both ammonia and nitrite read 0 ppm and nitrate is rising. Until then, keep nitrite down with water changes whenever it climbs above about 0.5 ppm, feed lightly, do not add fish, and consider a dose of Quick Start to speed the second stage. Nitrite at 2 ppm and above is an emergency: change half the water now. Adding a little aquarium salt also eases the effect of nitrite on freshwater fish.

The second spike of a new tank

Ammonia appears first in a new aquarium; as the bacteria that consume it establish, nitrite rises in its place before a second set of bacteria learns to convert it to nitrate. That nitrite spike catches keepers who stopped testing once ammonia fell. Reading nitrite through the cycle shows when both stages are working.

One bottle, 180 tests

A single reagent, a 5 ml sample and a short wait give a colour from 0 to 5 ppm. With 180 tests in the bottle the kit covers a full cycle of daily testing and years of weekly checks afterwards.

Fresh and salt water

Nitrite is as dangerous in a marine tank as in a freshwater one, and the kit reads both. Any reading above zero in an established tank points to a filter that has been disturbed or overloaded.

Frequently asked questions

What nitrite level is safe?

Zero. Any nitrite in an established tank is a sign the biological filter is struggling; in a cycling tank keep it below 0.5 ppm with water changes until the bacteria catch up.

Can I use the Nitrite Test Kit in a marine tank?

Yes. It reads nitrite from 0 to 5 ppm in both freshwater and saltwater aquariums.

How many tests are in the kit?

About 180 from the single reagent bottle.

Is nitrite included in the master kits?

Yes, both master kits test nitrite. This kit is for keepers who want nitrite on its own or need to replace a used-up bottle.

Is the API Nitrite Test Kit available in South Africa?

Yes — Jungle Aquatics in Fourways, Johannesburg stocks it and delivers nationwide; live pricing and stock are on jungleaquatics.com.

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South Africa's leading pet and aquarium store since 2007 — with the API range on the floor in Fourways, advice from people who test water every day, and easy ordering from anywhere in the country.

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