can anyone help with dying tropical fish?

I know this a cham forum but as iv had good advice for my cham I wondered if anyone could help.
Sadly one of my large silver dollars is dying and has been led on the bottom of the tank for a day now. He is alive and has a spurt of live when I tried to catch him. But it really is just a matter of time. I don't know why he suddenly took a turn for worst. But dont want to leave him in tank with other fish who may get ill/ nibble him. Is it kinder to kill him? If so how? Is it worth setting up a temporary tank for him to die in or will he suffer.

Any help appreciated
Lottie

I imagine you had your water tested and looked for white spots but if not do both cause you may have bad ammonia or he can have ich but you've probably ruled that out. I'm not sure if silver dollars are fresh brackish or salt but what do you keep him in

You can use clove oil to humanely euthanize it. I've had to do it before for a large flowerhorn. http://www.oscarfishlover.com/helpful-articles/euthanize-fish

I would do a 25% water change first, to see if he perks up. Have you done any water changes or excessive cleaning lately? Overcleaning can cause just as much damage as not cleaning, as you can rid your tank that of bacteria that convert ammonia to nitrite, and nitrite to nitrate (nitrosomonas and nitrobactir...sorry if spelling is off). If you threw off that balance, you will see changes in the fish. Too much ammonia your fish will become lethargic and stop eating, too much nitrite and they will gasp at the top or near areas of high flow. If your pumps are failing, your largest fish will be affected by low oxygen levels first. They will often sit near the bottom gasping, or in areas of high flow gasping (forcing water through their gills rapidly). This lack of oxygen can also be from too much heat, if your water feels warm, it is too hot! Warmer water holds less oxygen and can cause asphyxiation. If multiple fish are acting strangely.... gasping, twitching, etc.... you may have a toxin in your water and carbon should be replaced to help remove the toxin.

Silver dollars are freshwater but they get rather large. Important questions :
How long has the tank been set up
How long have you had the fish
How large is the tank
Have you had the water tested, if so how is the ammonia, nitrite, nitrate, KH, GH, and TDS levels
Is there reddening around the gills
are the fins tattered, if yes is there a pink/white film around the edge or cotton-like growth
are there spots on the fish
are there worms hanging out of the gills (thin filaments)
are any other fish affected
what other fish are in the tank
what is the temperature
what are you feeding and how often


Sorry to bombard you like that, just trying to help!

Thank you for your help.

Sadly zag died. I removed him from the main tank but he only lasted maybe an hour longer.

Hadn't doen a major clean in about 2-3months. Ammonia/nitrates were fine and no white spot. I think it was just his time to go.

I have had fish tank about 3 years. The silver dollar about a year in which time he went from 2p size to about 7 inches diameter. His brother is absolutely fine. No other fishes acting strangely but they did all turn cannible on poorly fish so perhaps he never really had a chance.

He was struggling to stay right way up (kept rolling) so maybe it was a swim bladder problem.

Thank you for your advice.

Had both fresh Cichlids and Saltwater fish for years. It's almost always water. Take a sample for testing. Don't feed but every other day and no matter how hungry or eager they look, just a pinch or two. Probably high Nitrates which is basically excess fish waste. Good luck!