We have 3 fairly large gold fish species, what size tank is adequate? One is showing signs of listing and black spots? They only get feed once a day and filter is changed often.

Help grand kids coming soon.

Thanks

I need a little more info and back ground info.
Are they round bellied goldfish or long and slender? Are they new fish/how long have you had them?
What kind of tank are they in now and how big are they? Goldfish are actually very,very large fish when full grown, so "fairly large" could mean two different things to us?
Have you done anything different to the tank (large water change/clean filter/clean gravel)?
Sorry to ask so many questions, but anything you could share with me will be helpful.
Kae

You may have too many fish.they need about a gallon of water per inch.in a 10 gallon aquariaum you should only have about 3 or 4 fish.hope this helps.