i have 2 big gold fish and one medium sized one why are they swimming at the top of the tank and looked stress?
ed out i didnt חο іf іt wаѕ tһе fill up ѕο i changed tһе аbουt half οf tһе fill up аחԁ now one һυɡе gold fish іѕ swimming regular bυt tһе οtһеr two аrе swimming аt tһе top. I һаԁ two οtһеr fish bυt tһеу died аѕ soon аѕ i рƖасе tһе һυɡе fish іח… i һаνе tһе rіɡһt sized tank аחԁ filter wһаt іѕ happening?
аחԁ tһе medium sized gold fish аrе growing Ɩіkе a besmirched mold οח tһеrе back аחԁ eyes

not enough oxygen in the fill up you need to call a pet shop where they sell fish and find out what is incorrect. i mean a real shop not the walmart type.
You may want to check the ammonia and nitrite levels, this can produce stress and may other problems. You can get test kits at your local fish store. Or they may have some disease, I don’t know which even if.
Maybe the small fish might be frightened of the huge fish or maybe the huge fish competes them for food so that the small fish get or the huge fish must had some disease .The 2 goldfish that died must have spread some disease which stressed them. There is endless theories but give them a couple or 4 days and see what happens. If the small fish is getting weaker remove him to a hospital tank and let him cure for awhile. Your huge fella will be fine.
how huge is your “right sized” tank?
im pretty sure you dont have the right sized tank considering as how goldfish like koi never stop growing
mines really 10 inches and still going passionate
but hes in a 75 gallon
it sounds like a fungal problem if its mold
u can get small tablets to place in the tank (it will stain the silicone usually) but it might work if that’s what it is
and you have to make sure you use a bubble wand because goldfish use a lot of oxygen and dirty fill up very quick
you also should check the ammonia because they secrete ammonia and have probably contaminated the fill up with ammonia
and you have to have at least 10 or 20 superfluous gallons of filtration for goldfish
ill just tell you what i have in my tank so you can just copy
its 75-80 gallons i have a nice amount of gravel a freshwater plant
a 30 gallon filter and 2 40 gallon filter 3 bubble wants (huge ones)
a radiator (they are cold fill up fish but if you get a radiator and place it on the lowest or following to lowest setting they usually do really well)
a light and i feed them a combo or flakes, bloodworms, turkey, and bologna
yes i know it sound weird but its really excellent for them and mine like it (by them im meaning my one goldfish and my other tropical fish, yes i know theyre mixed btw)
just dont feed to much turkey or bologna or it will contaminate your fill up becsue of all of the stout and ammonia will start to spike
only feed that like 2 era a week then 4 era flakes and one time bloodworms
excellent luck