I just found 2 of my L66 dead. I took some pictures to see if anybody has any suggestions as to why they died. There are some red spots on both of them. I tested the water yesterday an it was fine. And after I took the fish out of the tank, I did a 35% water change, just in case.
Maybe...
What are the tank inhabitants?Did blood came out of the mouth or is there blood on the bag/place you putted the dead fish for some time?If the second is true,then your fish have some kind of internal problems,most probably internal bacteria...
I forgot to mention those are two different fish. And I just got home and another two are showing the same symptoms. I thought they were also dead, but they were still breathing, so I moved them to a 10G tank. I don't think they'll make but at least I'll try.
The 75G has another L066, a L239, two L038, four L377, some cory trilineatus, rummynose and emperor tetras and some guppies. Only the L066 seems to be affected.