Can fry spread diseases?

[Alex.]

I have a 20 gallon with 6 guppies (4 females, 2 males) in it and they have tail rot. These were my first fish I bought so I didn't know what to look for when buying and I bought some with tail rot. But in the 20 gallon one of the guppies gave birth and now there is only 1 fry left that I have been able to get food to. I also have a 5 gallon with a guppy in it that serves as my quarantine tank. I have some Maracyn that I want to dose into the 20 gal, but I'm afraid that it will be too much for the fry. So my question is, can I move the fry to the 5 gal without worrying about the guppy that's already in there getting tail rot? Thanks in advance

[Colu]

I would leave the fry were it is and treat with maracyn it should be fine