WD Red with WD Purple in same NAS?

[Enquiries]

I’m a complete novice but after watching your videos I’m keen to get a NAS for photo/data storage and surveillance. What I’m not sure on is the hard drives to get. My thoughts are to have 2 WD Red with Raid 1 set up for photo/data storage and then 1 WD purple dedicated for surveillance. Is it possible to have 2 different WD (Red and purple) in the same NAS or should it just be one or the other?

Also in terms of surveillance storage, if I wanted to have constant recording at the highest quality for 2 cameras how much TB should I get for 30 days recording.

Thanks for your videos and advice.