Very Sick Ptychochromis Oligacanthus

[nadajdui]

This fish is incredible emaciated despite eating food on a regular basis. He was these long thread-like patches all over his body and on his fins. Not really sure what they are, some of them are as long as 1.5 cms. This all happened rather suddenly even though nothing has been added to the tank in well over a month. Just sort of at a loss, and wondering where I should start.

Tank stats:

Gallons: 80 US
Ph: 7-7.2
Ammonia: none
Nitrites: none
Nitrates: 5-10
Livestock: 11 Ptychochromis oligancanthus and 1 Geophagus ita..er...I can't spell or even pronounce the last part of the name, forgive me. Anyway he's in there too.

Plants: some healthy waterprite, foating
Filtration: 2 Aquaclear 70s, full power. Not sure if this counts as filtration, but there are some airstones going as well
Temperature: 26C/78F
Substrate: sand/some gravel
Decor: a few rocks
Anything added in the last week: No
Any chemicals added in the last few days: no
Feeding: twice, sometimes 3 times daily
If I've missed anything, let me know. I really wanna save this guy!

 

[nadajdui]

Had to euthanize.

 

[WILDER]

Do you mean stands of cotton hanging off him.
Being really skinny can be fish tb, internal parasites, old age.
What did it look like when the fish went to the toilet.
Was the anus of the fish enlarged or red and inflamed.