Special Weapon Abilities

So I know that powders give special abilities to weapons and armor, my question is how are they activated, because it seems whenever my curse it fully charged(As indicated by the water symbol) I get now sensory queue that it has activated. Is there some key I need to press to do so or what?

 

When your weapon's special ability is ready, you must shift + melee with it to activate it. Your armour's ability is always active however

 

Thanks, u the best

 

Closing thread as answer has been given.