2 fish in tank have ailments

Question
HI,
We have a 46 gallon tank, 75 degrees, Marineland Bio-wheel penguin power filter, water changes 15.3 gallons of the tank, once a month, the tank has been set up for a year, there were originally 4 fish, 1 Ryukin, an upside down cat fish and 2 algae eaters.   In the fall of last year we got 3 more Ryukin which were pretty small. One of them got very large very quickly, and the other 2 seemed to be growing normally.  Now  2 of the Ryukin seem to be sick.  About 3 weeks ago the very large one stopped swimming around and seems to be unable to balance.  He's been either lying around the tank or propping himself up in front of the little house in there, although he does move around a bit when you feed them or go over to the tank. We tried to look up diseases on the net and have been treating the tank with Sulfa TMP but that does not seem to be working.  Now we've just noticed that one of the other ones, a white one is starting to get black spots on her skin, fins and tail.  I also just read that that may be a sign of ammonia poisoning, what do you think? Thanks for your help!

Answer
Hi Lindsay;

It sounds like a swim bladder disorder. The swim bladder is a gas-filled organ inside the fish below the spine. It controls buoyancy. Problems with the swim bladder are very common in fancy goldfish because of their rounded body shapes. The swim bladder may malfunction as the fish grows because it can't stretch out in order for it's ducts to work properly. These disorders can be started or aggravated by high nitrates and/or from constipation due to a diet too high in protein.

First, about nitrate poisoning. Nitrates are the end-result of your tank's biological filtration. It is removed by water changes. Goldfish are very messy fish that need lots of room and frequent water changes to avoid nitrate poisoning. You have quite a few fish in there for a 46 gallon. A good population of goldfish for a 46 gallon is no more than 4 or 5 at most. Each goldfish needs at least 10 gallons of tank space per fish. Make a 25% water change and vacuum the gravel at least once a week. All tanks need it weekly but goldfish even more so. Twice a week wouldn't be a bad idea for your tank.

Lastly, diet plays a very important part in goldfish health all the way around. Most commercially available pellets and flakes are too high in protein for our largely vegetarian goldfish friends and it causes constipation. There isn't enough fiber. The swim bladder is connected to the digestive system and when they are constipated it can inflame the swim bladder. Start them out in their new diet by stopping all food for 2 or 3 days. They aren't going to starve. They will try to make you think they are starving, but they are just fine. This period of fasting will prepare their digestion by clearing it out. They may swim more normally after this stage. Then, feed them squished cooked green peas twice a day. Canned, frozen, whatever. Peas act as a laxative. They can nibble on them for several hours, unlike pellets and flakes that rot very soon after they are fed to your fish if left in the tank too long. Feed the peas for a few days and then you can re-introduce their regular food, but only a tiny bit. Continue to increase the flakes or pellets until it consists of no more than about 40% to 50% of their total diet. Feed the other 50% to 60% of their diet with a variety of veggies such as romaine lettuce, cooked carrots, cooked green beans, cucumber slices, slightly cooked squash and the peas. Again, let your fish nibble on the veggies for several hours. Regular food is different with so much protein and can't be left in there more than a few minutes. High fiber veggies are okay to nibble. It may take a few days for them to get used to the idea, but it will be very good for them in the long run.

I hope they do okay and get better very soon...

At Your Service;
Chris Robbins