We have had this bacterial problem with way too many fish since 2018. I've become firmly convinced of the need for UV sanitization of water. I am considering this in earnest, especially now, having lost so many precious, show kind and size fish. A turn key UV system would be $10K-$20. As a DIY, we might get away with several thousand $. Up until now, we have not used UV sanitization on our water.
The bacterial killer lives in our tanks+15K filter system and I am pretty sure it came with other fish, most likely in 2018 with the walking catfish from the wild, who were undertreated in QT. The 26K system of the two 4500's, one 1800, and the 15K sump hosts the majority of larger rescue fish that come and go. No surprise, with my lazy man QT procedures, that we have been losing precious, rare fish (while most of the cheap and hardy fish remain ok). But most of all since 2018. Until then, it had been far better. As for the what kind of bacteria, I am not saying it was the columnaris or only columnaris or that the columnaris was the primary cause, not secondary or tertiary. Some fish we have lost in 2018 and since then showed symptoms consistent with columnaris and some didn't. Columnaris is a complex animal and has several known strains, acting quite differently.
My gut feeling says reason #1 is that the wyckii was sickened and killed by a dangerous bacteria. A less likely reason is dirty 15K sump and as a result a high bacterial count in water column, but after I cleaned the 15K sump thoroughly twice over one year, there was no improvement whatsoever. Thus, I am inclined to discard this as the primary cause. A compounding factor it may be. I have planned to make a rearrangement in the sump, take out half the shade cloth media to make the hiding of detritus and bacteria harder and the vacuuming of the sump easier and faster and will continue cleaning the sump more frequently.
The bacterial killer lives in our tanks+15K filter system and I am pretty sure it came with other fish, most likely in 2018 with the walking catfish from the wild, who were undertreated in QT. The 26K system of the two 4500's, one 1800, and the 15K sump hosts the majority of larger rescue fish that come and go. No surprise, with my lazy man QT procedures, that we have been losing precious, rare fish (while most of the cheap and hardy fish remain ok). But most of all since 2018. Until then, it had been far better. As for the what kind of bacteria, I am not saying it was the columnaris or only columnaris or that the columnaris was the primary cause, not secondary or tertiary. Some fish we have lost in 2018 and since then showed symptoms consistent with columnaris and some didn't. Columnaris is a complex animal and has several known strains, acting quite differently.
My gut feeling says reason #1 is that the wyckii was sickened and killed by a dangerous bacteria. A less likely reason is dirty 15K sump and as a result a high bacterial count in water column, but after I cleaned the 15K sump thoroughly twice over one year, there was no improvement whatsoever. Thus, I am inclined to discard this as the primary cause. A compounding factor it may be. I have planned to make a rearrangement in the sump, take out half the shade cloth media to make the hiding of detritus and bacteria harder and the vacuuming of the sump easier and faster and will continue cleaning the sump more frequently.
