Looking at your system, I think hyposalinity is your best option. Any medications added will likely cause collateral damage and kill beneficial “bystanders”.
Copper is brutal to inverts and some fish won’t tolerate it either.
Many medications just won’t work. Ich is caused by a Protozoa. Most antibiotics will be ineffective as they target bacteria. Bacteria are prokaryotic organisms whereas Protozoa are eukaryotic organisms (for the record, humans are eukaryotic as well). The difference is critical as prokaryotes and eukaryotes have fundamentally different forms of metabolism. Antibiotics in general take advantage of the differences enabling us to kill off infections without killing ourselves in the process.
In medicine, eukaryotic infections ( malaria, fungal infections, leishmaniasis, etc) are much more difficult to treat as the medicine will more greatly impact the patient as well.
So back to ich (you can add brooklynella to this as well). If you choose an antimicrobial medicine, choose one that is used in medicine to treat protozoan infections. Chloroquine may work (in humans, it is used to treat malaria). Metronidazole may work as it has activity against trichomonal infections (another Protozoa). You will still probably damage beneficial microbes during treatment but may at least have a chance of success treating the infection.
Lastly, you could try to impregnate the food with the medication and feed the medicine directly to the fish. You may then be able to use a total lower dose and avoid some collateral damage, but the fish may not eat the food due to the taste of the medicine
In conclusion: for a FOWLR system, I think hyposalinity is your best bet
Copper is brutal to inverts and some fish won’t tolerate it either.
Many medications just won’t work. Ich is caused by a Protozoa. Most antibiotics will be ineffective as they target bacteria. Bacteria are prokaryotic organisms whereas Protozoa are eukaryotic organisms (for the record, humans are eukaryotic as well). The difference is critical as prokaryotes and eukaryotes have fundamentally different forms of metabolism. Antibiotics in general take advantage of the differences enabling us to kill off infections without killing ourselves in the process.
In medicine, eukaryotic infections ( malaria, fungal infections, leishmaniasis, etc) are much more difficult to treat as the medicine will more greatly impact the patient as well.
So back to ich (you can add brooklynella to this as well). If you choose an antimicrobial medicine, choose one that is used in medicine to treat protozoan infections. Chloroquine may work (in humans, it is used to treat malaria). Metronidazole may work as it has activity against trichomonal infections (another Protozoa). You will still probably damage beneficial microbes during treatment but may at least have a chance of success treating the infection.
Lastly, you could try to impregnate the food with the medication and feed the medicine directly to the fish. You may then be able to use a total lower dose and avoid some collateral damage, but the fish may not eat the food due to the taste of the medicine
In conclusion: for a FOWLR system, I think hyposalinity is your best bet