Stressed Goldfish?

Hi Jennifer, congratulations on having such an impressive specimen-I'm sorry to hear he's not feeling well but he seriously needs to be in a much larger tank-a foot long fish living in a 20 gallon tank can do little more than tread water which is akin to a person never getting any exercise I'm wondering if this is the initial effects of stunting-when a fish is kept in a container far too small to permit much movement their internal organs will continue to grow while their body remains static. Because he has been in a 20 gallon he has reached the limit of his growth potential? Just an idea but together with the other 2 fish this a very overcrowded place & no manner of maintenance is going to keep up with the toxicity that will be created.

Putting in a new filter has removed the good established bugs in the old one that eat the toxins so therefore possibly causing your tank to go into cycle again which is very stressful & potentially lethal. Your ammonia & nitrite readings confirm this-they should both read zero. You don't mention what type of Goldfish he is but if he's a round bodied fancy then there is a greater possibility of swim bladder disorders. I would suggest daily partial water changes of around 50% until your parameters drop to safe levels & please consider getting larger tank. If he is a streamlined fish then this is even more urgent-he will be suffering.

I would just add that if it is not possible to get a larger tank you might consider offering him on either your local Freecycle Group or Craigs List for his own good. someone will offer to adopt him & give him the space he desperately needs.

Best of luck to you both.

The problem is simple. Your tank is WAY too small for your foot long fish. That fish is probably a single tailed common or comet and it should be about 18" long. You've stunted that fish by keeping in a very small tank. That fish should be in a 75 gallon (long) tank with a very powerful filter. Actually, this single tailed goldfish is best suited for a pond.

The other much smaller goldfish will be ok in that small 20 gallon tank as long as they are the double tailed fancy type of goldfish. (The 20 gallon tank is the minimum size for 2 fancy goldfish only) From what you've described, the fish's internal organs are shutting down. This happens when a goldfish is forced to live in tank that is too small. The fish's organs continue to grow although the fish cannot. The result is that the fish's internal organs will fail and the fish will die.

Sorry for being so straightforward. Unfortunately, it's very common for people to keep goldfish in tanks that are too small. Throwing medication, stress-coat, salt and other remedies are not going to help. This will only add to the stress of the fish.

Your 20 gallon tank is severley over stocked. There is absolutely no way to keep 3 goldfish healthy in that tank. The minimum size your tank needs to be is about 125 gallons with an extremely powerful filter.

I hope your large fish will survive. Getting a much larger tank will be the only chance for survival, however. If you can find a goldfish pond for it, that's a good option, too.

a stressed out fish is not good have you added any recent changes to his enviroment?you might want to ask a vets opinion but he could just be getting old.

I suggest setting up a separate hospital tank and aggressively treat for infection with antibiotics.

Poor fishy. Wow, a foot! I hope everything works out. I can tell you really don't want to loose him. You seem like you're trying really hard. I hope it pays off.

What happened before he got sick? Did you move him or get new fish recently?