Is it possible to temporarily lock out one of the Macs in my house from my network. I know you can turn it off via the Admin Computer (mine), but that also affects my MacBook. I just need to block access from one Mac, not all of them.
You could turn the Wifi off on that Mac. I don't follow why that would kick your other Mac off the network, unless it's connected via network connection sharing, in which case I don't see how you can knock a computer off the network but still use it to share a connection.
Alternatively, you can turn MAC filtering on, if it isn't already, and just delete that computer from the access list.
I want to temporarily turn off Wi-Fi access to my brothers MacBook. He is in the teenage phase of his life where he doesn't listen to anyone and spends his entire day online. He's getting horrible grades in school cuz he doesn't study/do his homework (he's incredibly smart, but doesn't apply himself). If my mother tells him to do a few chores around the house, he refuses to do them. Therefore, I want to be able to have the ability to turn off/on the Wi-Fi on his MacBook.
AirPort pane, Access tab. You can even set up timed access so that the connection is available for specified hours (otherwise choose Timed Access anyway, and set it to every day, all day).