1. where

to add water to the lower filter fish tank? Water to the lower filter fish tank can be added from the main tank or from the bottom tank. There is no difference between the two. If the water is added by the connecting pipe, it will be more convenient to add water to the main cylinder, so as to prevent the bottom cylinder from overflowing due to too much water. If you use a bucket to add water, you'd better add water to the bottom tank, so you don't have to lift it too high. It should be noted that if you change the water, you need to add water to the bottom tank.

Filter cotton: Filter cotton is an essential filter material in the filtration equipment. It mainly plays the role of physical filtration. When the water flows through, the impurities inside will be blocked by the filter cotton, thus making the water clear. If the filter cotton is used for a long time, it will be blocked, so it needs to be cleaned, and if it is washed thin, it should be replaced.

2. Ceramic ring: The main function of the ceramic ring is to provide attachment for nitrifying bacteria, thus achieving the effect of biological filtration. Clear water is not clean, if there is ammonia nitrogen in the water, it will also poison fish, and biological filtration is to convert ammonia nitrogen through nitrifying bacteria, so as to ensure the health of fish.

3. Volcanic rock: Volcanic rock itself is a porous structure, so it has a certain adsorption capacity, which can absorb harmful bacteria and heavy metal ions in water, thus improving water quality, but it will not work after saturation, so it should be replaced regularly.