Can fish die without nitrifying bacteria in the fish tank?

Nitrifying bacteria will naturally appear as long as it takes a long time, so don't worry too much about fish during this period.

If you are afraid of affecting the water quality, change the water every few days to at least keep the water quality good until nitrifying bacteria form.

Nitrifying bacteria belong to autotrophic bacteria and can be regarded as producers. They include two completely different metabolic groups: nitrosomonas and nitrifying bacteria, including different forms of bacilli, cocci and spirillus.

Nitrite bacteria include bacteria belonging to Nitromonas, Nitrococcus, Spirillum and Phyllanthus. Nitrogen-containing bacteria include nitrifying bacteria, nitrifying cocci and nitrifying cystine.

These two types of bacteria are obligate aerobic bacteria, and both use oxygen as the ultimate electron acceptor in the oxidation process. Most of them are specialized and autotrophic and cannot grow on organic media.