7 Mystery Deaths Overnight

[Dallascowboys16]

So I've had my tank setup for a year and a half and haven't had a death in months. Well anyway 3 days ago I added a pair of Gardneri Killifish and always well until this morning. I woke up to SEVEN dead bodies in the tank. My first thought was that the killifish went on a physco rampage but then I remembered that I had done my 50% weekly water change yesterday and I thought it may have something to do with that. Before I went to bed (several hrs after the water change) all was well and all fish were alive and well. The fish that died were 1 juli Cory 1 otto 3 cardnial tetras 2 glowlight tetras. Also I tested and had ZERO amonia, Nitrates were 5-10, and nitrites were 0. Any ideas on what happened? The bodies looked kind of beat up and 3 were half eaten. Thanks in advance. Also the tank is Heavily planted with co2 injection and Dry ferts. Water is pristine and plenty of hiding places.

 

[Mifsud]

It is probable that the Killifish did this. Many male killifish are aggressive when kept in community tanks, especially if they're not the only of their kind.

 

[Dallascowboys16]

Ok he's the only killifish in there besides the female. So you really think that he did this? Is it possible for a small fish to kill 7 fish in a night?

 

[ukejoe83]

Oh ya it's possible, had a similar group of nite murders awhile back. Many fish rest at nite but some take advantage of that and hunt at nite.

Might not work for you but I now keep a nite light (moon light) on the tank so the resting ones can see and feel the hunters get near. I also feed them about 20-30 mins before the nite cycle kicks on.

And is your Co2 off at nite? That could be killer also.

 

[Dallascowboys16]

Yeah the co2 turns off when the light goes off and turn on 1 hr before lights on so it can become adequately dissolved so the plants can begin to use it right as light turn on. I left the killies in last night to see if any other fish are killed I'm going to keep them if there's no other deaths and If something similar happens again they're gone. I just paid 25 bucks for them at an auction so I wanted to see if I could keep them. I'm going to check for more missing fish now.