High scores are urgent! ! ! ! What if the fish tank is small but the oxygen tank is full? How to make it smaller?

There are only three goldfish in a 40cm fish tank, so there is no need to add oxygen tanks. Just take out the pump and change some water every day!

If you insist on using it, go to the place where the ceiling fan is sold (or the general hardware store) to buy a stepless speed change switch, connect it and adjust it. If you use the indigenous method, you can also find a 250ml mineral water bottle and tie some holes evenly on the bottle wall to cover the water inlet pipe.

If you feel that there is too much air output from the sand head, find a clamp to clamp the air outlet pipe, and at the same time clamp a nail and other things, and adjust the distance between the nail and the air outlet pipe to achieve the desired air output! If you want to wrap things in sand to meet the requirements, you can wrap several layers of emery cloth or sea surface. If it is dirty, wash it with dishware detergent, then rub it with salt, soak it for 10 minute, and then rinse it with clear water. I have used all these fish farming methods, which are economical and effective! ! !