Goldfish clamping/lethargic most the day

Hi, I've had two goldfish in my tank for 7 years (overstocked and small tank sadly, fish store regulations have changed). I was also a huge idiot and 3 weeks back cleaned my tank and replaced my

Is this fungus on the angelfish and if so best way to treat ?

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Growth on fins and lethargic

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health - Common goldfish with bleeding around face, gills and fins - Pets Stack Exchange

Goldfish Diseases Are Easily Prevented and Usually Treatable

Lethargic Goldfish - Bottom sitting : r/Goldfish

GF Dis F 51

Comet goldfish very lethargic, Freshwater Fish Disease and Health Forum

Comet goldfish very lethargic, Freshwater Fish Disease and Health Forum

Fast Moving &/OR Lethargic Behaviour

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