I am suggesting having it on hand. I said "Damaged fins can be more likely to get either bacterial and or fungal fin rot." I did not say the fish had anything needing treatment but is one begins to see more rapid disitigration andusually this is accompanied by whiteness, then one should medicate.
Here is something that I learned very early on when I began keeping fish. Thee actually have a union with rules. I know this is hadr to believe but consider when you set ou with a net t catch one specific fish in a tank. Rule 3, state any time you notice a net in the water chasing one of your other residents it is your duty to swim into the net. Another rule governs whem fish should get sick.
If you are going to get sick be sure to do it on a weekend as this makes it much more difficult to buy a needed medication.
Because I am privy to the rules, I assembled a medicine kit early on. It normally contains:
- Several antibiotics to cover gram negative, gram positive and broad spectrum treatments.
- Fristz Maracyn Oxy and Methylene Blue for for fungus.
- Metronidazole, Levamisole HCL, Fluebendazole, Praziquantel, and Quick Cure for assorted parasites.
- Natural items such as Salt, Almond leaves, Epsom salt and Rooibos tea (also used to stain water).
Don't get me wrong, I prefer not to medicate unless I know what is wrong or if things are at a point that my best guess is better than allowing fish to die. I do not pretreat new fish either unless I know it is needed. Medicating a tank stresses all the fish in it whether ot not they are suffering from whatever ails a specific fish or fishes. Strss is the precursor to making fish more susceptible to getting ill/infected with something. But I also know when it is something that will spread that the whole tank needs to be treated. When it is safe to just remove fish and threat them in a dedicated H tank I do so.
As a young kid I was a cub scout but never a boy scout whose motto is "Be prepared." When it comes to the possibility of having the treat fish I follow that motto.
edite for typos/spelling