Marine Ich- Do you really have to treat a fish for 30days?

[ColoradoBill]

So, I've been developing my quarantine process for my fish and I've been doing a lot of reading. I'm seeing a lot of people who recommend copper treatment for 30 days to completely eradicate ich. My question is, if we're treating the fish in a separate QT tank, wouldn't you only need to treat for 10 days or so? Maybe 14 to be sure? Yes, I understand that the copper only treats the free swimming form of the Cryptocaryon, but the life cycle of the parasite is only 5-7 days inside the fish. The copper should kill any free swimming parasites so as long as the fish is in the copper for over 7 days, all the parasites in the fish should have left, and the fish shouldn't be reinfected because the copper is killing any free swimming parasites that may infect it, right?
I understand that if you wanted to treat a tank (not a specific fish) you would need to treat for the entire life cycle so that any encapsulated cysts would be killed, but wouldn't it be a much shorter treatment time if you're just treating a fish?

 

[Saltyreef]

Hotrocks protocol calls for 14 days in copper power and then transfer to sterile QT.

 

[Nathan Milender]

So, I've been developing my quarantine process for my fish and I've been doing a lot of reading. I'm seeing a lot of people who recommend copper treatment for 30 days to completely eradicate ich. My question is, if we're treating the fish in a separate QT tank, wouldn't you only need to treat for 10 days or so? Maybe 14 to be sure? Yes, I understand that the copper only treats the free swimming form of the Cryptocaryon, but the life cycle of the parasite is only 5-7 days inside the fish. The copper should kill any free swimming parasites so as long as the fish is in the copper for over 7 days, all the parasites in the fish should have left, and the fish shouldn't be reinfected because the copper is killing any free swimming parasites that may infect it, right?
I understand that if you wanted to treat a tank (not a specific fish) you would need to treat for the entire life cycle so that any encapsulated cysts would be killed, but wouldn't it be a much shorter treatment time if you're just treating a fish?

You can also try the tank transfer method and go no copper if you want (for ich only). I use chloroquine, and in spite of people saying 14 days is enough I tend to go for 30. I am not particularly worried about ich, it just gives more time to see other disease, get them used to my food, give a good oral metro multi-dose. I usually do the last week with prazi as it clouds the water and then I can do a complete change before the next QT. If you are technically perfect, 14 days should be enough. I assume I am not.