How to easily make an oxygen tank in a fish tank?

1, preparation tools: mineral water bottles, straws and scissors. ?

2. Cut the mineral water bottle along the middle and take the first half.

3. Make a hole in the cover to insert the trachea. The inner diameter of the hose is 4 mm, and the outer diameter of the interface between the check valve and the air regulating valve is just 4 mm. Look, it is perfectly butted and does not leak.

4. Make a hole in the side and fix the sucker.

5, so that you can suck on the fish tank, complete.