6 year old healthy goldfish passed suddenly

[SirDonutATSM]

Have you tested your water?

Yes

If I did not test my water...

...I recognize that I will likely be asked to do a test, and that water tests are critical for solving freshwater health problems.

Do you do water changes?

Yes

What percentage of water do you change?

21-30%

How frequently do you change your water?

Every month

If I do not change my water...

...I recognize that I will likely be recommended to do a water change, and water changes are critical for preventing future freshwater health problems.

6 year healthy goldfish got home to find it dead in just 4 hours it had No symptoms tank is fine stress is low and was eating fine beside Passed fin rot that I believe I got rid of out of my tank and fins to damage to heal it’s was fine planning on doing a quarantine and a 100% water change But I don’t know what happen

 

[SilverArowanaBoi]

6 year healthy goldfish got home to find it dead in just 4 hours it had No symptoms tank is fine stress is low and was eating fine beside Passed fin rot that I believe I got rid of out of my tank and fins to damage to heal it’s was fine planning on doing a quarantine and a 100% water change But I don’t know what happen

What size tank did you have? Did you do a water change recently?

 

[SirDonutATSM]

What size tank did you have? Did you do a water change recently?

Tank is 750 litres I water change 1 maybe 2 times every month 30-40%
Had a few problem with other fish in the tank recently but I had seem to hold it steady So far though 2 goldfish have died the other a year maybe 2 old was in bad shape From a disease I didn’t expect it to live I plan on separating the goldfish 100% water change a filter and tank clean with hot water and then leaving it for a day or 2 to cycle and check it. I m use to fish dying but after seeing trauma or disease and almost always for a week at less but woke up this morning feed at the fish as normal everything look great came back 4 5 hours later to find the oldest goldfish picked clean And on the bottom haven’t removed it yet I’ll do that tomorrow with the clean.

 

[SilverArowanaBoi]

Tank is 750 litres I water change 1 maybe 2 times every month 30-40%
Had a few problem with other fish in the tank recently but I had seem to hold it steady So far though 2 goldfish have died the other a year maybe 2 old was in bad shape From a disease I didn’t expect it to live I plan on separating the goldfish 100% water change a filter and tank clean with hot water and then leaving it for a day or 2 to cycle and check it. I m use to fish dying but after seeing trauma or disease and almost always for a week at less but woke up this morning feed at the fish as normal everything look great came back 4 5 hours later to find the oldest goldfish picked clean And on the bottom haven’t removed it yet I’ll do that tomorrow with the clean.

I think you should do many more water changes than just once or twice a month. I think at least once every week. How many fish are/were in the tank?

 

[SirDonutATSM]

I think you should do many more water changes than just once or twice a month. I think at least once every week. How many fish are/were in the tank?

I plan on doing water changes more regularly just haven’t got around to doing more research. The number of fish what fish are in there is Changing often But right now it’s around 20 fish
Some peaceful some semi aggressive species but I never get many problems with aggressive behaviour between small freshwater fish

 

[FINWIN]

Sounds like chronic ammonia/ nitrate poisoning from water quality issues. Kills 'em fast or slow. Goldfish are major water foulers.