The Great Fish Purge

We have a fishtank in my office here at home, and we've had a good number of freshwater tetras and barbs in it. Until last night. Milady went upstairs last night, to check on the fish as part of our zookeeping rounds, and fish were dead. We're used to having one die every now and then, that's kinda the cost of running a tank. This was different.

We had lost 6 different fish last night, and two more after we did a water change and tank scrubbing. The rest are looking puny enough that they may well not make it long either. What is so troublesome is the suddenness of it. Yesterday morning, they're fine, now they're mostly dead. Very disturbing.