DROPSY!!

[BleuTheBetta]

I’ve tested it and it’s zero. I also use prime before adding it in. It only became an issue after I used nitrofuranzone/kanaplex treatment.

Ahh, okay. I’ll leave the rest to the professionals, I was just wondering if that was playing in.

 

[Kyanite14]

Depending on how much carbon you used, will determine how much medication was removed from the water by the carbon. A small cartridge might not be enough to remove all the medication. Residual medication can also sit in the gravel and leach out over weeks or months after treatment.

The best way to remove chemicals from an aquarium is by doing big (75%) daily water changes and gravel cleaning the substrate. After a week of this there shouldn't be any medication left and the filter should start to recover. However, you also need to clean the filter before and after medicating the fish. You do it before treatment to remove the gunk in the filter so the medication can work on the fish. You clean it after treatment to remove any dead micro-organisms and leftover medication in the filter.

It can take a couple of months for an aquarium to recover after treatment. This is common when antibiotics have been used. Adding a liquid filter bacteria supplement can sometimes help, but normally it's just a matter of waiting until the bacteria recolonises the aquarium.

If you use a filter bacteria supplement, add a double dose every day for a week, then pour the remaining contents into the tank. try to add the bacteria near the filter intake so it gets drawn into the filter where it belongs.

Good news! When I did my water change today I tested the water (last time I did was 2 weeks ago) and ammonia was 0!

 

[GaryE]

Keep the large water changes coming. It will continue to improve.

I find that if I can get columnaris to disappear with new arrivals, I can't ever put them in a community. It returns.
I don't have access to antibiotics, so those who do may have other experiences.
But it is a tough pathogen that sticks around. It doesn't always spread to other species, or other "purchase groups", but it doesn't always disappear either.Fish will grow and look good, but the dreaded spots will appear again even in good conditions.

As @Colin_T pointed out, dwarf gouramis are a whole other story. Wild types were delicate fish with a tendency towards ich if they weren't always very warm, but the farmed ones are plague pits. Iridovirus, bacterial infections, tb - they struggle.

 

[Kyanite14]

It never spread from the Gourami, and was actually pretty slow. I kept the water around 72 and it never really got worse than a white tuft in his mouth.