[sheren]

you mean you have 4 koralia 4s and 1 koralia 1?
yes

what brand like marineland or what
marineland

Have you done any more water changes? How is the color?
no more water changes and I can see in the tank, light green color instead of dark green and I could not see in the tank at first

This is really puzzling me since it happened so suddenly.
Is there anyone else in the house who could have put something in the tank by accident or a child. Things like air fresher in the room can make a difference.
already round up all of the suspect and no one did anything as far I know