When to treat the display tank?

I'm hoping to get some clarification about treating the display tank vs moving fish to a hospital tank. Rather than going into all the possible variables and details of my situation, I'd like to just look at this one question separately as a theoretical for now.

If every fish in a display tank, (tetras, rams, and discus) is exhibiting the same symptoms of bacterial gill disease, should I consider that a contamination of the tank itself and treat the entire display tank with antibiotics? I'm concerned that if I remove all of the fish to be treated in a hospital tank, and then put them back in the display, the bacteria that caused the initial problem will still be present. Or is bacterial gill disease generally only present in dangerous amounts on the fish themselves?

I do realize that treating the display will mean starting over the cycle.

Thanks,
Kesley

Bacteria, viruses, parasites, etc will only be 100% eradicated if you treat everything those fish have come into contact with. This includes filtration, glass, substrate, decorations, etc. If you want to be safe you are better off treating the display and do massive water changes to keep those ammonia levels down.

+1

If you maintain partial daily WC, after treatment start a new cycle won't be an issue.

Hi Kesley,
I just exercised this process , 130 g tank with 15 discus and 7 sterbai , i am treating all the fish in a Q tank with 2mg/liter of PP while i treat the display tank with much stronger PP together with filter and media ,i have done this 3 times every 4 days and i have another 3 treatment to go ,in a 22 days period , too early to say if gill fluke been eradicated or not but my filter media has been hammered and need cycling .

I think there are two separate topics here.

1. To cure the disease, using a quarantine tank usually works better. You can manage the dosage because the tank is smaller and doesn't contain other "stuff". You can make 100% water changes in a smaller tank, control the temperature, add salt - all difficult to do in a 130 gal tank.
2. To clean out the display tank is a different issue. Wiping down the surface and making a 100% water change will effectively drop the pathogen pressure down to where they're no longer dangerous. If flukes is a problem, running the tank without fish for 2 - 3 weeks will likely starve them out.

Good luck, Willie