Well turning your router and modem off at night does sav a little power bu its negligable the amount of power they use, your network maybe slow because when you turn your modem/router back on, it has to reacquire an IP address from the DHCP server, which can take upto 5 mins, therefore if you leave your modem/router on, it will keep the IP address and wont neeed to renew it everytime. If you get what i mean lol.
