It a standard action to activate each element. that not an interpretation that is the rules. But some GM will allow you to activate them at start of day and leave them going all day, other dms will not allowing you to only have the active in dangerous area, such as dungeons ect. Because you don't always have your weapons drawn while walking in town and other places less dangerous. you would scare off all the pesents and surely get thrown in jail. They are mostly useless in the long run because of that and energy resistance in monsters build up quickly and it basically = out to almost no damage and a waste of 3 rounds to get started, best bet is to go straight to +5 weapon then dr becomes a non-issues, you are also more accurate with that allowing you to hit more often and power attack into the mix. Add keen speed or holy or even bane depending on what you been fighting in AP.