Fish deaths and what to do next

[dalto]

So...I have an interesting situation.

Last weekend I finally got water in my first large tank.

I went and picked up a few fish. 6 2" Uaru amphiacanthoides. I acclimated them fairly slowly over the course of an hour and a half. I did this by placing the water from the fish bag in a large breeder box. The box was partially submerged in the tank water and I added tank water to the breeder box incrementally over the course of 90 minutes. After being added to the main tank I monitored them off an on for about 10 hours before going to bed. The fish were active and alert and showed no signs of distress.

When I woke up the next morning they were all dead. The tank is not cycled but 6 2" fish put a virtually non-existent bioload on a 200g tank. There was not enough ammonia to register on the API test kit.

My water is reconstituted RO/DI that is soft and acidic. ph 6.0, KH 3, GH 4, Temp 80F. Filtration is provided by two Eheim 2080's with extended spray bars providing quite a bit of surface agitation.

So, I have only been able to come up with a couple of things that could have killed them.

• Osmotic stress/shock from being moved from harder water to softer water even though they were acclimated pretty slowly.
• Some type of chemical in the tank.

I am trying to decide what to do next. My biggest issue is that I have no real way to test for the presence of a foreign substance. The only thing I can think of to do is buy a couple of hardy fish and see if they survive. I would prefer a solution that didn't risk the fish but nothing is coming to mind.


Thoughts?

 

[Delapool]

Do you know if the lfs had them for very long?

I can't think of much else as I assume from your profile you would of set these up before. Bit of a shock to lose them! Nothing changed over-night?

I would try that as well and get some hardy fish (preferably ones you want to keep imo).

 

[dalto]

Do you know if the lfs had them for very long?

I am not sure how long but more than a week. It was an LFS I don't go to very much. I located them and then went back later.

I would try that as well and get some hardy fish (preferably ones you want to keep imo).

Yeah, I picked up some young CB "G" brasiliensis from the LFS I typically use. They keep their SA fish in much softer water and those fish are quite hardy so we will see what happens. Probably not long term keepers but I should be able to grow them out a bit before they get too rowdy. I am not looking forward to chasing them around a 6ft tank though :|

 

[PB_Smith]

• Osmotic stress/shock from being moved from harder water to softer water even though they were acclimated pretty slowly.
• Some type of chemical in the tank.

I am trying to decide what to do next. My biggest issue is that I have no real way to test for the presence of a foreign substance. The only thing I can think of to do is buy a couple of hardy fish and see if they survive. I would prefer a solution that didn't risk the fish but nothing is coming to mind.


Thoughts?

That's really bites! I hate it when you finally find something you have been looking for and then something like this happens. I recently came across some marble hatchets and snatched up 9 total, of which sadly only three remain. I should have known better as about 25% of the batch at the lfs had obvious genetic "errors" and I should have passed, but you guys know how it is.

You could add carbon if not using it already to remove any suspected toxins, but I think it may be the first reason you listed.
Did you by chance test the ph and hardness of the water the lfs had them in?
If the lfs water was up near 8 or higher in ph and related hardness, you may have to approach it differently.

I think one approach to avoid the same thing happening is to test the water the lfs keeps them in and adjust your tank to closely match those parameters, then after the fish have been introduced and are settled in your tank, gradually adjust the parameters to the levels you want to maintain them at.

 

[dalto]

Did you by chance test the ph and hardness of the water the lfs had them in?
If the lfs water was up near 8 or higher in ph and related hardness, you may have to approach it differently.

I didn't test it but after they died I wished I had.

I think one approach to avoid the same thing happening is to test the water the lfs keeps them in and adjust your tank to closely match those parameters, then after the fish have been introduced and are settled in your tank, gradually adjust the parameters to the levels you want to maintain them at.

Yeah, if I get any more fish from there I probably will need to test the water and see what is going on then make a plan.

 

[Delapool]

This is out of interest but could say ph have fallen further at night? And even though they looked ok by day, this upset them too much?

I totally agree with the lfs water testing, I'm just curious as alas I don't get to set up many new tanks (not counting queries on how much work it would be to shift a 4ft tank half a foot further along the wall).

 

[dalto]

This is out of interest but could say ph have fallen further at night? And even though they looked ok by day, this upset them too much?

pH is pretty steady in that tank. Not much to effect it.

 

[Delapool]

Ok, no worries. Thanks for the info.

 

[dalto]

Well, the brasiliensis are doing fine. So I guess there is nothing wrong with my tank.

Must have been the acclimation after all.