I have a 200g tank and it has been set up for around 2 years. I have a powder blue, blonde naso and a saddleback butterfly. The naso and saddleback were added in last month.
Everything has been going well but yesterday all my fish started to act strangely. All werent eating as normal and swimming properly. The butterfly was just hovering and the naso was swimming at the wavemaker.
This morning the butterflyfish died and so i did a 25% water change. Then the 2 other fish start laying on its back and looks like its going to die.
My parameters are still stable. I dont know what to do. What could be the problem to this?
Everything has been going well but yesterday all my fish started to act strangely. All werent eating as normal and swimming properly. The butterfly was just hovering and the naso was swimming at the wavemaker.
This morning the butterflyfish died and so i did a 25% water change. Then the 2 other fish start laying on its back and looks like its going to die.
My parameters are still stable. I dont know what to do. What could be the problem to this?