Nighthawk R7000 - Monitor bandwidth usage of individual devices?

Hi everybody, I hope you can help.

As it says in the title, im wondering if it's possible to check the bandwidth usage of individual devices connected to my Nighthawk R7000 (AC1900)

Someone on the network is uploading ridiculous amounts of data every single day, to the point that over 2 weeks I have totals of:

70gb up

260gb down

At times the simple task of logging in to an online game will say "login failed, no connection" and playing online games will frequently disconnect or lagg immensely. 

My broadband connection is 200mb down 20mb up - so it's a total joke that these problems should be happening.

I understand one solution to my problem would be to block each device one by one, until the problem stops, but I have 6 people and atleast 10 devices... so this method would cause problems for everybody in the house.

I'm pretty sure some idiot has torrent software running in the background and set to run at startup, so they have no idea they're doing it.

If i could identify to device which is responsible for all this uploading, I could block it and wait for them to complain about having no WiFi.

Any suggestions would be greatly appreciated,

Thank you