My fantail swimming crooked

Question
My tank has been set up for approximately 6 months, the other fish seem fine, but the gold
fantail I noticed last night swimming sideways,
Tonight I did a partial water change, using the
conditioners, added a touch of aquarium salt and
cycle.  Should I put him/her in a separate tank
tomorrow.  I set up a one gallon tank tonight just
in case. In the tank 5.5 Gallon I have with the
fantail one calico fantail, one oranda, two corys,
and one otto.  None of them are huge. There is a
power filter for a ten gallon.  

Answer
Hi Nancy;

Poor little fella. He has gas! Fantails are fancy goldfish. Goldfish have unique digestive systems and they develop gas easily. They are also natural born gluttons so they often eat too fast and suck air into their bellies at the same time. They will turn on their sides or upside down because the gas floats and makes the fish flip over.

It is simple to treat really. You need some cooked and cooled green peas. Feed them to your fish and feed no other foods until he is feeling better. Feed the peas a couple of times a week after that to encourage good bowel health. It is good for all your fish.

Another problem you have here is that the tank is way too small for them. They are small now, but they will grow. Goldfish are deep-bodied creatures that make a lot of waste for their size. Gone are the days when it was acceptable to keep them in bowls and small tanks. Many people, including fish stores, still accept and teach this practice. Goldfish need a tank of 20 gallons or larger to thrive. Once they get 3 or 4 inches long they do best in ponds or tanks of 55 gallons and larger. If the fish store didn't tell you the truth about them it is a shame. These beautiful fish get to be 6 to 8 inches long and can live to be over 10 years old!

Until you can get them a larger tank (which should be soon!) make plenty of water changes to keep them all alive. Replace 25% of the water at least once a week. Vacuum the gravel at the same time. The highest safe population for any tank is one inch of adult fish for every gallon of water. This is "adult" fish because your fish are going to grow. The otocinclus and the cory cats will take up 4 adult inches of space by themselves. This leaves room for one more fish. At 6 to 8 adult inches, goldfish are just too much. Even with a power filter for a ten gallon tank, the fish have not enough room to move properly as they grow. You will soon begin to see illnesses and perhaps the death of the weakest fish to make room for the growth of the stronger. (*note* The old adage "fish only grow to the size of the tank" is a very cruel way to keep any kind of pet. They are living, breathing, feeling creatures that depend on us for their care and well-being).

With more room and plenty of water changes, your goldfish will thrive, grow, become more colorful, and be oh so happy!

Followups welcome

At Your Service;
Chris Robbins

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