Trouble shooting - friend's fish dying overnight

Atarius · Jun 2, 2019

Hi all

I'm trying to trouble shoot remotely for a friend who seems to be having some trouble.

Tank is a few years old, never had any similar issues, but for the last few days all the fish in their tank have been dying a few at a time overnight.

They seem to be generally eating fine, but some are hiding in rocks whereas usually they would be out and about. No other symptoms such as lethargy, heavy breathing or mucus.

They've tested parameters (and had some tested by the LFS) and that hasn't turned up anything untoward, and nothing appears to have swung sharply. I doubt they've tested for trace elements though.

LFS suggested a parasite (they don't quarantine) but there don't appear to be any symptoms of parasites.

All I can think is voltage leak? Inverts all seem to be uneffected so doesn't seem likely to be copper corrosion from a component or similar.

Any thoughts welcome!!

Mjrenz · Jun 2, 2019

A parasite is a definite possibility, some parasites can kill a fish before they even start to show physical symptoms. Have they noticed any of the fish swimming into the flow of a powerhead? If you can get some pics it may help

Also, a good place to start would be with a freshwater dip to see if flukes could be involved
https://www.reef2reef.com/threads/freshwater-dip.248898/

Atarius · Jun 2, 2019

Mjrenz said:
A parasite is a definite possibility, some parasites can kill a fish before they even start to show physical symptoms. Have they noticed any of the fish swimming into the flow of a powerhead? If you can get some pics it may help

Also, a good place to start would be with a freshwater dip to see if flukes could be involved
https://www.reef2reef.com/threads/freshwater-dip.248898/

Good shout, I'll ask if they can do a freshwater dip. I'll also ask about them swimming into powerheads.