:/   Ok. It is AWESOME that you now appear to have a filter. And I'm sure you are trying to do your best for them by getting a tank....but honestly that "tank" is way, way, way, way too small. If you can I would return it. It is only very slightly better than the bowl. I know we have given you a ton of information to take in but seriously; we know what we are doing. As stated above goldfish need a MINIMUM of 20 gallons for the first fish and 10 gallons (or 40 liters) for each additional fish. 40-50 gallons (160+ liters) MINIMUM for your four fish. Now I know it is expensive but it is a required part of owning any pet- you have to take proper care of them. If you can't take care of them properly you really should consider rehoming them. Now if you want to keep these fish alive you must change the water every day, almost all of it, and use water conditioner every time. Trust me- it would be MUCH less work to have them in a real tank.

  I am terribly worried about these poor fish and you should be too.

Please do something. If you tell me your location I will find you a used tank online, if you happen to live close to me I will give you a tank for free.

Ah. Very very far from me. Dang it! I'll look around.

Another option, given that from your previous thread I believe your fish are both single tailed (correct me if I am wrong there ), you could always re-home them to someone with a suitable pond and enough space, as these fish will grow to around 10 - 12 inches.

So if they are both single tailed, please do look at this thread, I made it specifically so people can understand about single tailed goldfish more; (Link is not visible to guests. Please register to view.)

Good luck!