my goldfish have red spot how do i cure them someone please help!!!!!!!!!

[wesling09]

hi i resently upgrade my goldfish from a 20 gallon to a 55 gallon fish tank and everything was fine until recently they started getting red spots and they started to stay at the bottom corner of the fish tank all group up together ..i had 13 fish in the fish tank and like 4 are not goldfish relative fish...dis morning 4 fish were dead so i need to cure this fast..i have check the ph and it was around 7.5 ...the n3 and n2 (i 4get wat is called but thats closed to it i think) was closed to 0 which the tester says it ideal condition .. pliz help me out

 

[dkpate]

The fish in the first pic looks pretty rough. Are his eyes cloudy and his fins shredded?
Did you cycle the new tank before you moved them? Did you acclimate them?