Does OTA apps consume lots of RAM ?

I have a HTC One X+ with Sense5 android 4.2.2 and I'm using lots of OTA apps like: Viber, Line, Fb messenger, etc. When checking memory using Clean Master, I always 78% (of 1Gb) or more without any running app. The phone still multitasking well enough but 22% of Ram left doesnt seem that much. Do you have any suggestions ?