I've been recently asked to switch from DPS to tank heal (when we actually start raiding) with another priest on the raid. I have just started to heal 5-mans (have the ilvl for heroics but that's for shadow) and have been having trouble on fights that require me to heal multiple people. Even when all the damage is on the tank, with me using PW:S, heal, and penance (with he occasional GH)my mana still just drops after 2 min or so. By the end of the fight im usually at about 5k mana.
I have been trying to keep haste/crit/mastery all at about the same (From what i read on EJ you don't just stack one secondary stat). I am worried about tank healing in raids and even heroics from the trouble im having in normal 5-mans.
Was wondering if anybody had any advice for me or tips to heal as disc.