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
that is soft and acidic. ph 6.0, KH
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.