Discus illness?

[Oli]

I have a group of 5 discus in a 300 litre. They have existed peacefully for about a year and a half now. The partner of one of the males has recently (past week) been hiding behind the driftwood not moving much. I assumed this was her new breeding spot as I had rearranged the tank recently, so left her to it. She has not been eating ans I began to get worried and today I came across her looking like she was dead. I began filming when she started to move again, but something looks off. I’m not sure how to explain it but it almost looks like swim bladder or something. All parameters are perfect, nothing has been introduced to the tank or changed in the way of maintenance/food. It was one day she was swimming at the front of the tank when I came up to it, and the next she remained still behind the driftwood?

She is currently “floating”, staring up at the ceiling. She is still breathing but not responsive.

 

[GaryE]

If the water change routine has been good, and all maintenance done, it may just be the same 'things go wrong' that we face. Sometimes fish sicken for internal reasons that we can only guess at. They have complex bodies just as we do.

But if the maintenance slips, or if your routine is too rigid and doesn't increase as the fish get bigger, then bad things become more likely. You sound like you're doing it right, but it's always good to review how you're doing things.

 

[Oli]

Urgent update***

The fish is almost certainly about to pass away, taking her final breaths - unfortunately I have no way to euthanise right now . I have also noticed problems with with the remaining discus. The blue tiger has turned almost black in colour. One of the red discus had white poop.

There is clearly something bigger at play here - please can someone offer help for the rest of them!

 

[Colin_T]

Are they eating well?
What are you feeding them?
there's lots of plants in the tank so they should be eating them and shouldn't have an intestinal issue but they might have.

The black fish is stressed or sick or both.

White poop can be worms or hexamita (internal protozoan infection).

The first fish look skinny, deworm them and treat with metronidazole if they aren't eating properly.

 

[Fishfunn]

It definitely looks like an internal infection of some sort is going on. We need to determine if it is parasite-related or not.

I like Colin_T's advice, using metronidazole for a possible internal protozoan infection.

Have you added any new fish or plants lately? Your other fish look healthy.