How did my fish die?

[FishKeeper72]

My littlest goldfish died! I have no idea how he died. But the creepy thing about this is that his tail fin, dorsal fin, and mouth had been torn off! I don’t know if this was one of my fish who did it, or if he got stuck to the filter? I have 3 other goldfish, 5 dojo loaches (3 of them are up to 10 inches), and 2 small Clown plecos. Please help! I don’t want any of my other fish to die if I have a murderer in my tank!

 

[mrsjoannh13]

It might be that other fish nibbled a bit after he died.

Can you post more info about your tank (size, water parameters - ammonia, nitrite, nitrate, pH, GH, KH, info on water changes)?

 

[Colin_T]

Can you post more info about your tank (size, water parameters - ammonia, nitrite, nitrate, pH, GH, KH, info on water changes)?

Besides this information,
How long has the tank been set up for?
How long have you had the fish for?
Have you added anything to the tank in the last 2 weeks?

------------------
Wipe the inside of the glass down with a clean fish sponge.

Do a 75% water change and gravel clean the substrate every day for a week. The water changes and gravel cleaning will reduce the number of disease organisms in the water and provide a cleaner environment for the fish to recover in.
Make sure any new water is free of chlorine/ chloramine before it is added to the tank.

Clean the filter if it hasn't been done in the last 2 weeks. However, if the filter is less than 6 weeks old, do not clean it. Wash the filter materials/ media in a bucket of tank water and re-use them. Tip the bucket of dirty water on the garden/ lawn. Cleaning the filter means less gunk and cleaner water with fewer pathogens.

Increase surface turbulence/ aeration to maximise the dissolved oxygen in the water.

Post pictures of the remaining fish.

 

[FishKeeper72]

Besides this information,
How long has the tank been set up for?
How long have you had the fish for?
Have you added anything to the tank in the last 2 weeks?

------------------
Wipe the inside of the glass down with a clean fish sponge.

Do a 75% water change and gravel clean the substrate every day for a week. The water changes and gravel cleaning will reduce the number of disease organisms in the water and provide a cleaner environment for the fish to recover in.
Make sure any new water is free of chlorine/ chloramine before it is added to the tank.

Clean the filter if it hasn't been done in the last 2 weeks. However, if the filter is less than 6 weeks old, do not clean it. Wash the filter materials/ media in a bucket of tank water and re-use them. Tip the bucket of dirty water on the garden/ lawn. Cleaning the filter means less gunk and cleaner water with fewer pathogens.

Increase surface turbulence/ aeration to maximise the dissolved oxygen in the water.

Post pictures of the remaining fish.

My tank is a 75 gallon tank, my fish have only been in there for about 2 weeks. The one who died was the smallest goldfish and someone gave us him for Christmas ( he was just a bait goldfish for turtle and other fish eating animals) the nitrate levels are a little higher then they are supposed to be ( but that’s because the tank is going to the nitrate cycle thing for new tanks) the PH is higher than I want it to be. Ever thing else seems fine. I was just going to let the tank cycle through for a couple of weeks and see what happens. I don’t know if I should do weekly water changes or wait for a couple of weeks.

 

[itiwhetu]

So what are those readings, pH etc.

 

[FishKeeper72]

So what are those readings, pH etc.

Nitrate: between 0 and 20 ppm
Nitrite: between .5 and 1.0
GH: 0
KH: between 120 and 180ppm
Chlorine: 0
pH: Around 7.8

 

[itiwhetu]

Ideally the nitrites should be 0 and the pH closer to 7, once this tank settles down and finishes it cycle things should be fine. Sorry for your loss.

 

[FishKeeper72]

Ideally the nitrites should be 0 and the pH closer to 7, once this tank settles down and finishes it cycle things should be fine. Sorry for your loss.

Thank you for helping

 

[Naughts]

You should do a large water change as the nitrite will be poisoning the other fish.
Also test for ammonia.
Water changes will not stop the cycle happening as beneficial bacteria live on hard surfaces, not in the water column.

 

[FishKeeper72]

You should do a large water change as the nitrite will be poisoning the other fish.
Also test for ammonia.
Water changes will not stop the cycle happening as beneficial bacteria live on hard surfaces, not in the water column.

But it’s a new tank

 

[Slaphppy7]

New or not, if you have nitrItes, your tank isn't cycled, and at that level of nitrItes, a WC is in order...

 

[FishKeeper72]

New or not, if you have nitrItes, your tank isn't cycled, and at that level of nitrItes, a WC is in order...

Ok. Do I need to do an emergency water change or can I wait till tomorrow

 

[Slaphppy7]

The sooner the better...be sure to match the tap temp to the tank temp, and if using a siphon, treat with enough Prime for the volume of the tank

 

[FishKeeper72]

The sooner the better...be sure to match the tap temp to the tank temp, and if using a siphon, treat with enough Prime for the volume of the tank

Ok

 

[Essjay]

But it’s a new tank

That's the problem - a new tank hasn't grown all the bacteria necessary to keep ammonia and nitrite at zero, unless the tank was fishless cycled with ammonia before fish were put in the tank.