Hi everyone!
Brand new fish keeper here from France. Nice to meet you all!
I have a 60l/15gallon planted tropical aquarium.
Started cycling it for a week before planting it.
Cycled it for 4 extra weeks until all parameters in the right ranges.
Introduced 3 cory catfish (1 bronze, 1 albino, 1 spotted -they call it "pepper" in France). The shop said different colours would be fine together. Same day added 5 neon tetras. Everyone seemed fine. Bronze cory was super active and unafraid from the start. The other two hid a lot, which I believe is normal at first.
2 days later, we introduced 5 more tetras and a couple (male and female) dwarf gouramis. We're stopping there as I believe the biomass is maxed out.
48 hours later, I found the albino cory dead at the bottom of the tank. I've not noticed any aggression from the gouramis, or any issues between the fish. The tetras stick together, the gouramis explore alot but general stick together in the same areas, the corys ignore everyone and just hoover up the bottom of the tank.
Only think I noticed was the albino at the beginning would swim up a lot to the top area of the tank, and sometimes when he was on the bottom, he sort of suddenly turn on his right side, "spaz out" a bit (sorry for the term, but I can't think how to explain it), then swim off.
I rechecked water parameters and everything looks fine, everyone else looks healthy.
Any ideas what might have happened?