my first problem was my new young redcap oranda had shredded tail ,<tailrot) and a day later my 2 calico ruykins were covered in whitespot,,i just started a treatment for the tailrot as i thought the poor oranda was getting bad fast but 6hrs later im really worried about the white spot,,the 2 ryukins and oranda are in the same tak as i dont have another tank,,,will the ryukins catch tailrot as the pet store said i will have to wait 7 days before using the anti white spot as ive just started the medication for the rot.

You might want to treat the white spot with a temperature raise to 82 gradually and add salt 1 tsp per gallon of water.
Then treat with a oral, medicated fish food.  Jungle puts out a great product.   OR
Melafix can be used also with the salt treatment and will treat tail rot.

Yeah, allow your fish to get completely healthy before adding any other fish in with her! She might get a bit stressed by it and get worse again otherwise. Too bad you lost those two others ):