Many people are unprofessional.
I've had it before, just like you.
How many fish will die if the water is changed once?
Later, I asked a professional.
1, not all water can be changed, only two thirds can be changed.
If you want to change all the water, you must first release new water.
Put it in a fish tank for two hours, and then remove the chlorine.
3. The temperature difference between the new water and the previous water should not be too big.
Change the water like this
You wouldn't have died.
Also, from the perspective of geomantic omen, the position of the fish tank should not be misplaced, otherwise,
There may be bankruptcy at home.
You can watch the video of Feng Shui master Wang Chunlin.
It's not bad to learn some knowledge of Feng Shui by the way.
I wish your family harmony, happiness and health!