4 Goldfish in 65 lite bi-orb........fallen ill

Question
Hi, I've had this tank and fish for over 5 years now, introduced them gradually and never had a prob until now, the largest is around 8 inches now.

Bascially introduced a fancy goldfish around a month ago, noticed the water was getting cloudly so decided to do a water change but whilst doing this also cleaned the gravel very thoroughly-since then the new fancy goldfish has died and the other 4 are now staying at the bottom and not eating for 3 days now......had the water tested at pet shop and he gave me some salt solution stuff(2 tabelspoons worth applied over 2 hours) also some fish tonic/medicine and also told me to add 2 tablespoons of rock salt.....went back agin the next day and was told to wait a week until another water test and not feed the fish for 2 days, thing is they are still not eating and are staying at the bottom but look ill-is there anything else I can do?

Thanks
Darren

Answer
Darren,

60L=15 gallons US.

One goldfish requires 25 gallons US (100L) to survive and you've got 4 of them in your tank, and wonder why they are having issues?

Worse, they are over 8".  Each one requires 50 gallons when over 3" of proper filtration.

For five years, things were fine, ... I doubt that.  They have been surviving, but not comfortably.  They are breathing their own sewage, because no filter can appropriately filter the water for them.

Nitrates, nitrites and ammonia are probably off the charts.

Change out 50% of your water asap.  Change out 25% of your water every other day for a week after that.

Don't add the petstore's garbage to the tank...you don't need that stuff.  Just clean the water, gravel, substrate, filtration...they will recouperate somewhat, but in the long run you truly need to give these fish a bigger tank.

Happy fish-keeping.