Update for you.
The dwarf cichlid dies 2 days later
and I lost 2 more Cardinal Tetra
But the others seem to be doing a lot better. The bellies are getting fatter and they are a lot more active.
The tails on the Cardinals are slowly coming back but very slowly, I'm wondering if the stress of everything has brought on a case of finrot which is why the Cardinals tails disappeared in the first place, but they went suddenly, not gradually
I have some fin rot treatment so will start it soon.
One question I have though is that I have just added a piece of wood to my tank today and I am expecting to have some tannins released and am using the carbon to help filter out the tannins, but I need to remove the carbon to start the finrot treatment.
Am i safe to allow tannins in the tank? but wont water changes to remove tannins be removing meds at the same time?
Shall I just let my water go yellow whilst treating and only water change when the treatment is complete?
The dwarf cichlid dies 2 days later


But the others seem to be doing a lot better. The bellies are getting fatter and they are a lot more active.
The tails on the Cardinals are slowly coming back but very slowly, I'm wondering if the stress of everything has brought on a case of finrot which is why the Cardinals tails disappeared in the first place, but they went suddenly, not gradually

I have some fin rot treatment so will start it soon.
One question I have though is that I have just added a piece of wood to my tank today and I am expecting to have some tannins released and am using the carbon to help filter out the tannins, but I need to remove the carbon to start the finrot treatment.
Am i safe to allow tannins in the tank? but wont water changes to remove tannins be removing meds at the same time?
Shall I just let my water go yellow whilst treating and only water change when the treatment is complete?