The so-called ecological tank is to build a small ecosystem, so the essential element is: 1, producers can choose some algae plants, which are sold in the general flower and bird market. 2. Consumers can choose 1-2 small fish. 3, decomposers, you can add some humus to the bottom of the pond, or sludge in the pond, which contains a lot of fungi and can be used as decomposers. The nitrifying bacteria you mentioned is an autotrophic bacteria that can be synthesized by chemical energy, and it will also be contained in humus and sludge. In addition, it should be noted that the water in the bottle should not be too full, and some air should be left. Just do as I said above, and finally seal the bottle mouth and put it on the balcony, which is an ecological small bottle.