I agree with Henry and think I mentioned Praziquantel, which is the relevant active ingredient in API General Cure.
- I think if you have or can get Praziquantel it is a good choice to cure the infected fish.
I was under the (mistaken apparently) impression PraziPro is Oxybispropanol and <5% praziquantel by weight.
(Oxybispropanol is listed as an inert solubilizing agent, though I found it listed as EPA Pesticide Chemical Code 068604.)
Whereas API General Cure is the one with Metronidazole (an antibiotic), I am assuming that is the “metro” Henry is referring to.
(API General Cure is according to its label 80% table salt, 10% Metronidazole (an antibiotic), 5% Praziquantel and 5% silica amorphous.)
(API apparently uses table salt as its solubilizing agent.)
I think the underlying problem is the high DOC, as demonstrated by the PP treatments.
Yes, one option would be to remove the critters to a quarantine/hospital tank for treatment.
This would allow you to attempt something short of removing the driftwood.
I have to say realistically though, total pain though it may be the driftwood is going to have to come out and you are going to have to really go after it with a wire brush and screwdriver, knife, ice pick, whatever and anything that moves, wobbles or gives is going to have to be removed. After that disinfecting, the wood with PP or bleach will be required.
- The advantage in using PP is of course the visual confirmation of the disinfection.
Removing the wood will also allow you to treat the tank with whatever cure you choose including 5 or 10-ppm treatments with PP as an option. 30-minute treatments with 10-ppm PP are effective and reasonably safe. After 29-minutes the PP is neutralized using standard dose of dechlorinator, this can be done 5-days in a row.