R12 Translate balances for a ledger set

Hi community,

New to R12 and I have a client that has a need for secondary ledgers (different calendar from parent company) each secondary ledger (7) is in its respective currency.  I then created a ledger set that includes all 7 secondary ledgers.  I have read that R12 allows the translation of balances in a ledger set.  I have a few questions, do I have to add a reporting currency ledger to each secondary ledger and to the ledger set to run translation? Can I run translation on the already existing ledger set (7 secondary ledgers)?  Do I need to create a default