I've had a mysterious loss of fish in QT over the past few days. It's a 30g long tank, seeded with sponge filter that was running in my DT sump for about a month. QT was set up before fish arrived. About 3 weeks ago, I placed two flasher wrasses, a diamond goby, a possum wrasse, a tail spot blenny, a 1.5" two spot bristletooth tang, and a small small potters angel in this QT. That's a lot of fish for a 30g, but they are all small, and I planned to keep a close eye on them for four weeks and then move them to a 220g DT.
The QT had the sponge filter from the DT, various size pieces of pvc, a power head, and a HOB filter running. The fish all acclimated well enough, and were eating live black worms, LRS, and frozen mysis. After a week and a half, all seemed well.
Then, at about 12 days of QT, the potters started acting strangely, swimming along the surface of the water. There were no apparent signs of any parasites or infection. It did seem like it was losing color. I dipped it for flukes, and nothing showed up. There were no signs of injury. It was still eating. It was not swimming into the power head, just swimming along the top of the tank. None of the other fish seemed to have anything wrong with them.
On day 14, I lost the potters. It looked fine, just found it dead in the morning. The other fish were still behaving fine. Parameters were all "normal" for my usual setup. I did a 50% water change, and waited.
On day 16, one of the flasher wrasses was dead. No warning, just dead. Again, no signs of anything abnormal. I moved all of the fish to a new QT, seeded again from a sponge filter. Since I didn't see any sign of parasites or disease, I chose not to start ramping with copper. On day 18, the remaining flasher showed signs of significant fin rot on it's tail - so I started kanaplex, furan-2, and metroplex. That fish died the next day.
Here we are on day 20, and the possum wrasse was found dead this morning. Seemed fine yesterday, was eating. No signs of anything external. Again, parameters all check out as acceptable.
I am left with the diamond goby, the tail spot blenny, and the tang. I've been wondering if the tang was just picking the other fish off, but I haven't observed that behavior, and the other fish didn't show any signs of attack, other than the flasher wrasse that had a tattered tail. The goby and the blenny seem fine, as does the tang. All three are eating well. I've continued with the antibiotics, but I am not sure there is an infection in the tank.
Thoughts? Perhaps I should have isolated the tang, but since I was watching carefully and I did not observe any aggressive behavior, I thought it was ok. The fish all seemed to be getting along in the relatively small space after two weeks, but then started dying off.
Is there a usual suspect for what seems like a silent killer? Can it be that the tang is picking them off? What's my best course of action at this point?
The QT had the sponge filter from the DT, various size pieces of pvc, a power head, and a HOB filter running. The fish all acclimated well enough, and were eating live black worms, LRS, and frozen mysis. After a week and a half, all seemed well.
Then, at about 12 days of QT, the potters started acting strangely, swimming along the surface of the water. There were no apparent signs of any parasites or infection. It did seem like it was losing color. I dipped it for flukes, and nothing showed up. There were no signs of injury. It was still eating. It was not swimming into the power head, just swimming along the top of the tank. None of the other fish seemed to have anything wrong with them.
On day 14, I lost the potters. It looked fine, just found it dead in the morning. The other fish were still behaving fine. Parameters were all "normal" for my usual setup. I did a 50% water change, and waited.
On day 16, one of the flasher wrasses was dead. No warning, just dead. Again, no signs of anything abnormal. I moved all of the fish to a new QT, seeded again from a sponge filter. Since I didn't see any sign of parasites or disease, I chose not to start ramping with copper. On day 18, the remaining flasher showed signs of significant fin rot on it's tail - so I started kanaplex, furan-2, and metroplex. That fish died the next day.
Here we are on day 20, and the possum wrasse was found dead this morning. Seemed fine yesterday, was eating. No signs of anything external. Again, parameters all check out as acceptable.
I am left with the diamond goby, the tail spot blenny, and the tang. I've been wondering if the tang was just picking the other fish off, but I haven't observed that behavior, and the other fish didn't show any signs of attack, other than the flasher wrasse that had a tattered tail. The goby and the blenny seem fine, as does the tang. All three are eating well. I've continued with the antibiotics, but I am not sure there is an infection in the tank.
Thoughts? Perhaps I should have isolated the tang, but since I was watching carefully and I did not observe any aggressive behavior, I thought it was ok. The fish all seemed to be getting along in the relatively small space after two weeks, but then started dying off.
Is there a usual suspect for what seems like a silent killer? Can it be that the tang is picking them off? What's my best course of action at this point?
