Help. Need to protect my kids from the nasty stuff on the internet.

Hi. I'm a father of a 12-year-old girl, a ten-year-old boy and a six-year-old boy. All are very active on our computers and phones. They love Youtube and Mindcraft and other games.We have super fast internet (fiber, gigabit).I'm looking for a parental control system (preferably hardware that won't slow our internet speeds down) to restrict violent and pornographic material. But also looking for a system that helps me monitor time spent on devices, etc.Anything out there y'all are liking?The only thing I've found is Disney's Circle. But it has conflicting reviews (I guess everything has conflicting reviews these days).Thanks in advance for any insight. - Steve via /r/Parenting http://ift.tt/2eFgNYF