[Orion]

Welcome to MFT!

Adding the water from the 2 goldfish really didn't do anything to cycle the tank. For starters, very little bacteria actually live in the water column, the vast majority of bacteria live on the surface of things in the water. The substrate, decorations, filter media, and even the tank walls. Secondly, being from a carnival, I personally doubt that the water they kept those fish in was properly cycled to start with.

Some people say that the parasite that causes ick is always in the water. Some people say it's not. The fact's are that when fish are stressed, from things like being introduced into a new tank, brought home from the LFS, or are sick, this lowers their immune system and can allow the parasite to cause ick. So it might be possible that the new fish could have brought ick into her tank, or just the stress of the new surroundings or new tank mates allowed it to take hold. Either way, this is a perfect reason why a quarantine or hospital tank is a good idea. It gives new fish a chance to show any signs of illness, and get used to new surroundings which makes transfer into the main tank much easier on them. Also once fish are in the tank, don't add the water from the LFS with the new fish into the tank. You don't want to add what ever else might be in their water into your tank.

85 degrees is the right temp for treating ick for tropical fish, but make sure your reading about treating ick for goldfish and not tropical fish. Goldfish can survive higher temps for a while, but too long can cause damage because they are a cold water fish. I can't advise you much more on this part because I'm not that familiar myself, so just besure to research on them!

Good luck!