I would not describe my aquarium system as parasite free. I would describe it as parasitic controlled however. I try to choose fish that are healthy to start with. I do not QT them in a separate system but rather I acclimate them in my 20 g long sump. That way they acclimate to the water conditions in the tank that they are going to be in but they do not have to adjust to that while dealing with the stress of the bullies who already live there. When I do introduce them into the display, I try to introduce multiple fish at the same time. That helps spread out the bullying. Also I do it at night with the moonlight LEDs on. That way the original fish go to bed while the new fish can learn their new surroundings.
Anyway, I have not had a parasitic outbreak in years. I should also point out that my display has been set up since 2016 and the live rock has been in my tanks for 20 years. That means my tank system is very stable which is important.
Anyway, I have not had a parasitic outbreak in years. I should also point out that my display has been set up since 2016 and the live rock has been in my tanks for 20 years. That means my tank system is very stable which is important.