About 2 weeks ago, I had purchased 6 angel fish and added them to the tank. Over the course of 5 days I had lost 3. The other 3 seem to be doing fine now.
4 days ago I had done my usual weekly water change except for two main things. It was 2 days earlier and about 10% more than the usual 25% change since I had forgot it was draining. Anyways refilled water as per usual, temp about the same +/- 1'C. Before bed I had noticed my apisto agassizii male hiding, gasping rapidly and not eating. One of the females was also gasping but was still eating.
Next morning, 1 male apisto and 2 cardinal tetras dead. Female looking even worse. Got back from work and found female dead and 3 more cardinals dead.
Next day 1 cardinal, 1 pygmy cory, 2 emperor tetras and 1 scleromystax barbatus dead.
Today I got back from work and found 2 gold tetras, 1 cardinal tetra and my other female agassizii dead. Also, one gold tetra is turning dark black and will probably go soon.
No medications or anything different have been added to the tank since I arrived.
Other fish in the tank include 2 other apistos, congo tetras, threadfin rainbows, galaxy rasboras, black corys, royal whips and red whips. All remaining fish seem to be okay for now.
Anyone know what might be going on? I also noticed 2 cardinals breathing rapidly but not near the surface. Also when I found my pygmy cory dead, it had red gills. There is one in the tank swimming lifelessly also with red gills and a bulging eye. What's going on this time?
Sorry for the long read but thanks for all help.
Edited by moses123, 05 April 2017 - 09:23 PM.