Sick over medicated fish.

[Hum]

I recently took up feeding and caring for the 3 goldfish in my home.One of them had problem with fungus in fins so I put the medicine for fugus- however I put too much.Later I changed the water but now all my fish are sick with one have cloudy eyes and fin rot;the other(oldest like 3-4 yrs)has a strange bump on it’s tail as well as (grey?) coloured scales appearing;the last one still has fungus on it’s fin and gills are red(with strange bubbles in them).They’ve been like that for the worst part of around 3-4 months now.I tried test the water (it was too hard with a high Ph and hardness) I tried treating the water but it seemed to have no effect.I put cloudy eye medicine and am going to change the water soon.However I’m pretty sure the best option would be to euthanasia them as they aren’t getting better.But my family member won’t allow me to do that because of moral reasons.What do I do?

[LookoutTrout]

Hi there, sorry to hear about your troubles. I won't comment on medicine as I don't know much about it.
The best option for the fish may just be going back to the care routine they had before, then waiting to see if medicine is needed and which one first. If you have been asking advice in a shop then they may have been more interested in selling you stuff than helping you.
An extra water change or two might be immediately helpful to dilute whatever is making them ill. I suspect the nitrogen cycle has been interrupted and ammonia is making them sick, do you have an ammonia test?

[plankton]

Welcome to the forum.
As above, get a water test kit and test for any problem areas like ammonia, nitrite (and even possibly nitrate).
It would also help to know the hardness of the water (goldies do better in hard water).
How big is the tank, and which goldies are they (fancy/comet/common)?

[black ghost]

Hi, welcome to the forum.

Goldfish are tough fish in some ways. They might be saveable…..

Can you get a nitrate reading? If the nitrates are very high a large water change could make things worse. If the nitrates are low it would help.

Can you post some pictures?
How big is the tank? And the fish?

What are the actual pH and hardness values?
And of the tapwater?

How often has water been changed? How much? When was the last time? Do you add dechlorinator?

What filtration do you have? And do you renew any of it?