Amount of sleep necessary

I have heard different things about the amount of sleep an adult person needs; please advise me. I would like to be awake more often to chant but find myself falling asleep and weak of will power. Thank you!

I have heard different things about the amount of sleep an adult person needs; please advise me. I would like to be awake more often to chant but find myself falling asleep and weak of will power. Thank you!