Discus fish- fast breathing- dark colored

[Paoparodi]

Hey everyone!

Today I woke up and looked at my tank and I saw one of my discus fish, (the dominant one) breathing really fast and moving it's mouth like he was running out of O2!

Then I saw that one of my discus (the one that used to be the weakest) was now the new dominant one... He chases the other 2 discus, I have 3 in the tank (250 lts).

I'm thinking maybe they had a fight for dominance and he lost, and now he is feeling stressed, that could explain it's behavior.. Hope is not a disease or bacteria!

I changed half the water of the tank and O2 more than usual... I'm waiting to see how he reacts...

Does anybody know some case like this? What do you think it could be..? I need help...

 

[LostInFish]

I think if they all looked good at one point in your tank you where lucky because they need a min of 6 to apply the pecking order and not over stress one individual. I would get more discus depending on there size and how big your tank is of course. Discus are very aggressive sometimes and need to have a group to take out its anger. I have had discus for 2 yrs and have tried to do 3 discus and it can be done but you need to have a Breeding trio for that just random discus will cause problems as you can see. Good luck and remember to do water changes regularly because if not your discus will fall I'll very fast in toxic water.