I have a 1" demasoni cichlid in my 55gallon. He was eating fine when i fed him in the morning (dainichi sinking), and now he is floating/swimming on his side at the top. His fins are not eaten up or anything. His coloration may be slightly darker. im not completely sure though. 
Did a 20% water change 4 days ago.
Whats wrong with him ?
There is also a lot of hiding spots in my tank, and i'm running 2 penguin 350's w/ bio wheel
The rest of my fish are acting normal.
Just did a water test..
Nitrate:20
Nitrite:0
Hardness: 150
Alkalinity:180
Ph: 7.8
Water temp is 78-80 degrees.
Any fixes or tips to make him better?
Please help me! i dont want him to die!!
PS: I looked all over the internet, and most sites said he has "float." but he doesn't eat floating foods.
Did a 20% water change 4 days ago.
Whats wrong with him ?

There is also a lot of hiding spots in my tank, and i'm running 2 penguin 350's w/ bio wheel
The rest of my fish are acting normal.
Just did a water test..
Nitrate:20
Nitrite:0
Hardness: 150
Alkalinity:180
Ph: 7.8
Water temp is 78-80 degrees.
Any fixes or tips to make him better?
Please help me! i dont want him to die!!

PS: I looked all over the internet, and most sites said he has "float." but he doesn't eat floating foods.