Sick Fancy Goldfish :(


I've had my fancy goldfish for 2 years and he has suddenly gotten really ill. I keep him in a 10 gallon tank with gravel and another small tetra fish. I noticed yesterday that he would couldn't swim up and would remain on his side. His tail and dorsal fins have red veins on it and appears to be thinning on the end which I assume is fin rot. I noticed white build up on him and immediately thought it was the ich, so I used a method that has worked in the past by using garlic to raise their immune system and cleanse the water. I left it like that for a day then realized my misdiagnosis and thoroughly cleaned the tank and put him back in. He is still not swimming but the white build up on him is gone. His fins still have the rot, and the red veins as well. I did notice that he won't open his mouth, he's not his usual, mouth always moving and eat anything that moves, self. I waved a piece of garlic in front of his mouth to eat and spent 20 minutes trying to get him to pay attention but he didn't move at all and seemed completely disinterested. I'm really worried, help please. Here are some pictures of him just sitting after I thoroughly cleaned it.


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Madeline Peterson

Firstly, your tank is not large enough, although I definitely appreciate you not having him in a tiny bowl. A single goldfish needs at least 20 gallons. The stress may be making your goldfish sick.

Secondly, tetras are community fish, and you should have at least 3 of them or they get stressed. Stressed tetras will sometimes nip tails, and that can cause infection.

What is your water quality like? Ammonia levels? Nitrites? Nitrates? pH? Temperature? Hardness?


A two year old fancy goldfish should be MUCH larger than the one in the pictures. That fish is stunted from living in too small of a tank.

Fin rot will eventually kill a goldfish - but not at the stage your fish is in. Your fish has multiple issues probably caused by a breakdown in it's immune system so it's not the fin rot ... but probably an overall breakdown of the immune system causing multiple symptoms. So what I'm saying here is that what's causing your fish to behave this way is probably due to some other problem you can see. Perhaps internal. And, if it's a internal parasite, it will be next to impossible to get rid of once the fish's immune system is compromised and the parasite has taken root.

First ... I recommend pulling him out of the 10 gallon and putting him into a 20 gallon rubbermaid trash can. Get two of the trash cans ... and give him 100 percent new water each day. Just pick him up out of the water and plop him into the next trash can - empty, clean, and fill the can he came out of and fill it with new water - then move him to that one the next day. This is an old Chinese goldfish breeder's trick called ... wait for it ... "new water every day" and this new water will fix A LOT of problems that goldfish have.

In addition, I'd treat water with API General Cure - really, not enough symptoms here to figure out the specific cause and "General Cure", aside from having a very bad marketing name - is actually pretty good stuff.

Treat the water for parasites too.

And buy some "medicated" food.

None of this may work though.

Alaina Leigh

The red veins on the fins is very concerning, and indicates septicemia. I would do a large water change and medicate immediately. That's just me, others will probably disagree on the medication, but I'm worried the septicemia will progress further. If you catch it in time, your fish can recover.


Fancy goldfish need a minimum of 20 gallon per fish, but personally considering how large they can get, I feel 30 is more suited to them. Goldfish also have a very large bioload, which means you need very good filtration and regular water changes, especially so when you have a goldfish in a 10g, which is far too small. At that age he should be much bigger, which indicated his growth has been stunted due to the tank size. Red veins in the tail (if out of the ordinary and not just their coloration) can be a sign of septicaemia, due to high ammonia levels in the tank. I’d suggest you go and buy a large (20g+) storage tub to keep him in, make sure you keep the filter running in there and it would also be beneficial to get an air pump running too. Do large, daily or second daily water changes and medicate with something other than garlic. I’m not sure of the best medication for septicaemia but I’m sure somebody else can help there.

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