Rhom in trouble

[chomp chomp]

I have a rhom that i have had for 11+ years. Diet of smelt, krill and earth worms. Fish is approx 11-12" and maybe 8" tall.

nitrite.3
Nitrate 12.5
Ph 6.5

Fish is solitary in 120 gal, ehim2028, hagen 70 powerhead.

Anyways, fish has not eaten since end of Nov ( around the supermoon)
Fish still swims and charges at glass like normal.
Fish started to have a swolen belly on its right side that quickly manifested to both sides.

My pics are not the beat and the glass is dirty but looking for help as to what is going on. Local zoo could not advise but a reputable aquarium shop said mostlikely a tumor if nothing has changed.

I have tried to feed a shelled peas but will not touch,
Tank is currently yellow from furan2 treatment. Today is the 5th day since treatment. Any advise is appreciated.

 

[Charney]

does that read your tank does have a readable nitrite level?
definitely looks bloated. The fact that it started on one side worries me more for tumors but really need to make sure water quality is on check first.

 

[chomp chomp]

does that read your tank does have a readable nitrite level?
definitely looks bloated. The fact that it started on one side worries me more for tumors but really need to make sure water quality is on check first.

You are correct, there is a readable nitrate level but definately not too terribly high. I rechecked this morning at it was the same.
I am going to do another cleaning since the medication is done.
The fact that it is up is bohering me. It is not eating nor producing any solid waste.
It head is loosing the fat store and becomming concave. I really have had zero issues for almost 12 years.
The fish was a wild caught fish and was about 6.5" when i got him 4-25-05. Age is unsure sonit could be at the end of its lifespan. Depressing nonetheless..