I have 4 photos in 13gal buckets in a ~30gal RDWC system. Even previous grows without CO2 yielded huge plants. With CO2, growth is explosive.
I used 3" return PVC, was afraid of all the stories about roots ending up tangled and/or in the res.
This shows the plumbing:
This isn’t the best view.
Here’s a thread about my system: