I've had this tank setup like this for over a year. Prior to being in this 420 gallon they were in a 240 gallon (a bit less stock and smaller size, of course). This tank gets water changes 1-2 times per week and the filtration is fairly massive with four Eheim 2262's and a giant wet/dry filter run by an Iwaki 55RLT. The water parameters tested good.
Okay, this morning I just woke up to find my motoro breeding pair DEAD. My 2' long tigrinus is having labored breathing (I thought it was the salt so I didn't add salt yesterday after my 40% WC). The second day of the cloudy eye I had lost my 12" henlei female, but I attributed that to stress since the male motoro was chasing her around. Now, I know it's related. Yesterday, I also added a half dose of melafix. Today, I will proceed to clean filters, transfer fish to a spare 215 gallon and...... I really don't know. What's next?? This is the worst loss that I've had and I'm not sure what the next step is. This motoro pair recently had it's first litter of 4 pups.
Things that I've changed recently:
Added one new 7" NGT
Added one new 14" niger cat (found out later that this fish was with natives recently collected - might be the problem!)
Switched to Seachem Safe powder from Prime liquid about 2 months ago
I put 2 sponge filters in the sump about 3 days ago, but these were brand new from the LFS. (wanted to seed these filters for another tank)
My best guess at this point is that the niger or NGT brought a "bug" with them. I know the guys that I picked them up from (2 separate tanks), and I trusted them which is why they were not quarantined. Now, I found out that one of them (niger) was housed with recently collected Texas Cichlids. I'm guessing parasites or bacterial. What should I do next?? I'm thinking Clout, but I don't want to unnecessarily stress them out any more. I've lost too much.
Thanks MFK!