White patches and unbeatable fin rot?

I’ve been trying to diagnose these problems for 6 months at least. It all started from either zebra danios or guppies from Petco I didn’t quarantine. I suspect the guppies since they have slowly died off, only 3 left now. Some died from bloating, some died from wasting away. Some developed stringy poop and died. One developed a bent spine but took over 4 months to finally pass away.

After seeing very stringy poop, from everyone including the Pleco, we determined it must be internal parasites. I’ve treated with 4 rounds of Levamisole and 4 rounds of Prazipro. Since then, I haven’t seen any stringy poop. Also have not lost any fish since then.

The remaining symptoms are white patches on the zebra danios backs, and white fin rot on the guppies. Both of these symptoms still present and continually progressing after Levamisole and Prazipro. The patches come and go on the danios, but they never go away. The fin rot does not go away despite very clean water and every bacterial med out there. Danios have almost completely stopped breeding. The small fish in the tank seem to have stopped growing. I’m starting to suspect a mycobacterium infection (aka Fish TB). Pics of the danios below, thanks for any and all advice.

If you have been treating tanks with anti-biotics in an attempt to treat fin rot, you probably have drug resistant bacteria in the tank now. The first and only treatment for fin rot is cleaning up the tank conditions and adding salt.

As for the danio, the white marks on her body look like scars. The milky white stuff on the edge of her fins is excess mucous caused by something in the water irritating her and causing her to produce more mucous.

What are you putting in the tank water?
What is the ammonia, nitrite, nitrate and pH?

Do a 75% water change and gravel clean the substrate every day for a week. Make sure any new water is free of chlorine/ chloramine before it's added to the tank.

Don't add any chemicals to the tank for a few weeks and see how it goes.

Colin_T said:

If you have been treating tanks with anti-biotics in an attempt to treat fin rot, you probably have drug resistant bacteria in the tank now. The first and only treatment for fin rot is cleaning up the tank conditions and adding salt.

As for the danio, the white marks on her body look like scars. The milky white stuff on the edge of her fins is excess mucous caused by something in the water irritating her and causing her to produce more mucous.

What are you putting in the tank water?
What is the ammonia, nitrite, nitrate and pH?

Do a 75% water change and gravel clean the substrate every day for a week. Make sure any new water is free of chlorine/ chloramine before it's added to the tank.

Don't add any chemicals to the tank for a few weeks and see how it goes.

Click to expand...

Thats just how the Danios look, they have a white border on their fins. She's old, at least 3 years.