Cleric domain power auras (or any activated auras)

[setzer9999]

Various Cleric domains grant domain powers which are Su type abilities that involve auras. These abilities are all standard action to activate unless otherwise noted, as the Cleric class rules state, but I'm not seeing where it says what type of action it is to turn it off. I'm assuming free, but not completely sure and can't find it in writing.

Unlike Paladin auras, these are limited in the length of time they can be active, so I'm also not sure if they can stack if you activate more than one at a time. Do you have to turn one off before turning another one on?

[The Elusive Jackalope]

Nothing prevents you from having more than 1 aura active at a time if you have multiple domains granting different auras to you, but they must both be activated with seperate standard actions. Upon carefully checking the rules I only find that (Su) abilities require a standard action to activate and nothing is said on the action to dismiss the effect. I would assume a standard action, since dismissing an active spell and lowering spell resistance both require standard actions, and that would be what the (Su) auras most resemble.