Colombo Test Kit - Nitrite (NO2)
Nitrite (NO2) is produced from the breakdown of ammonia in the filter. Nitrite is highly toxic to fish, but is usually removed from the water by the bacteria which live inside the filter.
However, in new ponds and aquariums, or if the filter bacteria are damaged, the nitrite level may become toxic. The only way to know what the nitrite level is by testing the water with a Nitrite test kit.
Regular testing is required especially when setting up a new aquarium or pond as the test kit will inform if there might be excessive nitrite levels - which might lead to nitrite poisoning of livestock in the aquarium or pond.
Colombo Nitrite Aquarium Test Kit contains 40 tests. Full testing instructions included in the box.