African Butterfly fish is sick - Please Help!

[joneill]

I have a 90l freshwater aquarium with gravel, artificial plants, filter, air stone, heater and thermometer. The temperature of the water sits around 25deg Celsius and my ph level is 7.5

I have had my aquarium for almost a year. This morning when I switched on the light, I noticed my butterfly fish was not in his usual spot but facing down in between the leaves of a plant. When I touched him he wriggled and swam away but is swimming in loops. Then he stopped swimming and started to sink very slowly to the bottom. I left him for a while then saw him lying on the floor on his side so I nudged him again and this time he went crazy, swimming backwards and forwards and in loops. Now he is floating upright against the side of the glass about halfway down. He is still breathing but looks to be in distress. What is wrong with him and how can I help him?

 

[Mumma.of.two]

Hi and welcome!
Do you own a test kit?
What at your ammonia, nitrite, nitrate?
When was the last time you did a water change?

 

[joneill]

I tested the water this morning and all levels are healthy. Did a 35% water change a week ago. All my other fish (pleco and platies) are fine so don't understand what happened.

 

[Mumma.of.two]

I'm sorry when you say healthy, what are the numbers? Or are you using strips? The first thing to do when something is off (bad readings, sick fish, etc) is a large water change with temperature matched water.

 

[lornajane89]

How is your fish? Sounds like a swim bladder infection if he cant keep upright.