One of my goldfish acting wierd

Right now one of my goldfish is acting very strange, he was fine earlier today, he ate and acted fine. It wasn't until earlier I noticed that he was at the bottom of the tank not doing anything. I touched him to see if he was dead but he started to swim a little and then just stop and float bumping into things, just kinda dragging around. I checked the ammonia and it read 0.25 ppm which I believe is intoxic ammonia, correct me if i'm wrong. Anyway there doesn't seem to be any thing physically wrong with him, but he has never acted like this before. He has sat at the bottom of the tank at night, I just assumed that he was sleeping, but he has never been like this. The other goldfish are fine. Let me know if you might know what's wrong or if I am just peranoid. Thanks!

 

Any amount of ammonia can be toxic and can be harmful or fatal to fish.

When in doubt do a water change. And as ammonia is present, I'd use Prime as well to detox what is left.

 

how many goldfish are in your tank, and are they fan tails or comets? how big/old are they, and how long have you had this one?

I ask because that's how mine are when it's too cold for them. They can survive at 65, but i've found mine to be much happier healthier fish when I keep the tank closer to 70-75.

 

0.25 ppm may or may not be toxic - depends on if it's free ammonia or ionized ammonia (ammonium). The tests don't differentiate between the two (Seachem Ammonia Alert does) so any ammonia must be considered toxic. The pH also plays a large role in the toxicity - total ammonia doesn't change, but it converts between the two freely. The higher the pH, the less ammonium there is and thus the more toxic he water is.


As for what's up with the fish.... Mine will rest near the bottom somewhere. They find a little eddy and just chill. Have you moved things around in the tank? Goldfish are very smart and will find places to rest. One of mine sits a couple inches off the sand, face to face with an easter island head. Weird.

 

What kind of goldfish are they and what do you feed them? If they are fancy goldfish, it could be a bit constipated. Fancy goldfish, because of their body shape, are prone to digestive issues. Try fasting the goldfish for a day, then feed a bit of a pea. Watch to see if you can tell if that goldfish is pooping normally or not.