Not sure why the other 3 gave up, everything was fine water quality wise and fish seemed normal then just started dropping. They were still in the growout tank when this happened and hadn't been moved to one of the larger tanks, not sure if that played a role or not.
The lone survivor was lost unfortunately when I had to overwinter my 1100g indoor pond elsewhere and it wasn't being kept properly heated by the people watching it. The Lima and TSN in the pond survived the temp drop but the Planiceps couldn't handle it, major bummer and I moved the pond back out of their watch immediately after.
Been away from the fish game except for my SAL which is at 11yrs old now for a while but would really like to get more involved in the community again. Lots of OG catfish people have been gone a while due to life unfortunately. Love your tank by the way bro! Been seeing a lot of your threads of the 4500g