Thanks again for the great replies Christina.

Hi there! A 3-gallon tank is really small for goldfish. You’re probably having a water quality issue in your tank – it’s pretty difficult to maintain good water quality in a small tank like yours.

Have you tried testing the water for ammonia, nitrite, and nitrate? My guess is one of these water parameters are probably high and making your goldfish sick – most likely ammonia. You’ll want to buy a larger tank for your goldfish as soon as possible. See my goldfish tank guide for suggestions.

Definitely test those water parameters to see what’s causing the trouble (visit this article on water testing if you need help). Once you’ve found the issue, change a portion of the water every day. It’s important your goldfish are in a healthy environment before we can treat the disease itself (otherwise, your goldfish may not recover).

Once water conditions are healthy again, take a look at this article on common goldfish diseases. Does it look like your goldfish has any of these?

So happy you find the site helpful! I do try my best to ensure each article is as thorough and complete as possible.

But I do understand your concern about floating and sinking foods – both have their benefits and disadvantages. Many goldfish hobbyists I know don’t recommend the floating variety because they can cause swim bladder problems in fancy goldfish (their internal organs are pretty squished together, so gulping air from the surface can cause buoyancy trouble). On the other hand, sinking foods can dirty the water if your goldfish don’t find them in time!

Which to feed is a pretty tough debate. In the end, I guess it all falls under personal preference. 🙂

Hi Freddy,

I definitely agree with you there! Most times, I’ll just test for ammonia, nitrite, and nitrate as well. I don’t usually have to test for pH unless I find other problems in the tank – like rising ammonia or nitrite levels. Ammonia is more toxic when pH is high, while nitrite is more toxic at lower pH levels. So it’s good to know what’s going on in the water when you have these sorts of problems.

And like you, I also prefer liquid test kits. I just find them to be more accurate, and I don’t mind the extra steps (dripping drops into the test tubes) or waiting time.

Thanks for reading!