Was wrong with my fish

[Emma2120]

I have a fancy goldfish in my 80 litre tank, im a bit worried iv had him over year now.

He spends alot of time at the top of the tank. I dont normally but the tank light on because my room is well lit. But tonigh i decided to but the light on for a few hours as it went dark. I came up to bed to find my goldfish at the top of the tank with what seems to be a blister? Can fish burn from the light ? Or is it becasue he is at the top of the tank. For what i can see he doesnt have his back sticking out of the water and there is a gap between the water and the light of a few inches. I turned the light off immediatly but he is still at the top.

Please help i dont no what to do.

 

[Emma2120]

Jus realised i posted this on the wrong catagorie

 

[Mattyfelts]

Goldfish have huge bioloads and shouldnt be in a 20 gallon, they need big tanks. how often do you do water changes, feed, type of lighting, and do you use a heater?(you shouldnt) what are you using for filtration?

 

[Emma2120]

I do a water change atleast once a week. I feed him every morning just asmuch as he can eat within a few minutes. The filter came with the tank it is a moray aqua one 320 ( says this on the box) and the light is built in the hood of the tank i dont really no what the light is but it says on it that its a phillips 36w/865? And no i dont use a heater.

Iv looked this morning and the blister seems to have gone down and he is swimming around. and his fin is up right.

 

[Mattyfelts]

its still to small for him, water changes help but seriously could be dangerous. What kind of goldfish? Use AqAdvisor - Intelligent Freshwater Tropical Fish Aquarium Stocking Calculator and Aquarium Tank/Filter Advisor and see what your stocking level is at and if its overstocked look into a bigger tank. People believe goldfish will grow to their tank size they are put in while in reality, their body stops growing and organs continue. This causes quite the painful death for the goldfish.

 

[Emma2120]

Oh no i didnt realise. Ill take a look at the link thanks for your help. Do u think thats whatswrong with him because of the tank size?

 

[Mattyfelts]

Its the tank size and his high bioload, its probably ammonia burn. maybe find a good used tank online, some used filtration and media so itll be seeded and a fast cycle and throw him in a new one once its ready?