fish bloat

Question
My son's goldfish are struggling to swim below the surface of their tank and keep floating to the top. It is a 20 litre tank we have had set up for 6 months with just 2 fish. The PH level is always Alkaline & I struggle to get the balance correct. I try to change 15% of the water weekly but must admit it has been a couple of weeks since I last  did it.

Answer
Hi Brooke;

It sounds like they may be having a swim bladder problem. It is usually diet related in goldfish from constipation. But swim bladder problems can also be aggravated by stress and can also be caused by genetic deformity. Since they are both affected at the same time I doubt it's genetic. Let's see what we can do...

Stop feeding the fish for 3 days. They need to clear their digestion. They will not starve to death. It's only temporary and it's for their own good right now. After their 3 day fast, feed only cooked peeled peas. Squish them a bit into little chunks. Feed twice a day, only the peas for 3 days. They should start feeling better by then.

Another thing they need is consistent water quality. Weekly changes are important, especially with messy guys like goldfish. But, change 25% every week. Your tank is very small and 15% isn't going to be enough. Many experts recommend only 10% to 15% but I always personally recommend 25%, even in larger tanks. It's all about keeping up with our messy fish and removing their waste before it makes them sick.

And...don't mess with the pH! Your fish will become accustomed to what the tank tends to be. Trying to change it all the time causes fluctuations that are very stressful. Stability is what we are looking for, not a certain reading on a chart.

Finally, your fish need a larger tank. Goldfish are very messy guys that need at least 40 liters (about ten gallons) per fish with a power or canister filter. It is a common misconception that goldfish can live in small tanks. They need plenty of space for their waste to be distributed until the next water change as well as enough room to swim for exercise and good health. So start shopping for an 80 litre tank or larger. Your fish will love it!

Here is a good web page about goldfish care;

http://www.firsttankguide.net/goldfish.php

I hope they do okay...

At Your Service;
Chris Robbins