Dead After Moving to DT

[SamS]

I had 2 spotted hake in my QT for close to 2 months and finally decided to move them over to my DT. They were acclimated to the QT for about 45min and were very healthy and happy in there for the entire time. They ate right away and never showed any signs of illness or distress.

When I moved them into my DT (which has been running for well over 5 yrs) I acclimated them for close to 2hrs and seemed fine when I went to bed. When I checked on them the next morning, they were swimming in circles and breathing very heavy. I tried to get them back into QT (where they had been very happy), but they died during reacclimation. All the other fish in the tank are very happy and showing no signs of distress.

Water quality was showing 0ppm ammonia and nitrite and 10ppm nitrate.

Any idea of what could have gone wrong?

 

[BlueMoonFox]

Salinity shock? How closely matched are the param like temp and salinity from QT to DT?

 

[scooter31707]

what other fish are in the tank. there could have been some aggression during the night hours.

 

[ca1ore]

When I moved them into my DT (which has been running for well over 5 yrs) I acclimated them for close to 2hrs

There's really no good reason for any acclimation when going from QT to DT. By the time you're ready to make the switch, QT water should be identical to the DT water. In my case, I just wait until the lights are out, then net and transfer.

 

[SamS]

Salinity shock? How closely matched are the param like temp and salinity from QT to DT?

They are almost identical. One runs at 30ppt the other runs between 30 and 31 depending on the day. Same with water temperature.

I do acclimate though because pH in my DT has always run closer to 7.6 where my QT runs closer to 8.0.

So that is really the only difference, but I would think that 2hrs would be enough to acclimate them to that.

Only other fish in the tank are a small pinfish (which the hake were much larger than) and a hogchoker (so an extremely docile animal that isn't going to do any damage even if it wanted to)