I have done both, put it in my res. or top feed from a 5gal bucket with a pump, and a piece of 1/2" hose with a valve on the end. Plug pump in with valve off then control flow with valve.I still use cheaper aquarium pumps but on the bigger side of them. I believe the pump I use now is an eco, around 645gph. I oversize my pump and control flow with valve for my dtw as well.
I run 16 2gal cloth pots, 50/50 coco/hydroton,dtw with
Botanicare PBP and some additives, 25gal res changed once aweek. On res change days, I flush with diluted tea from a 5gal bucket as described, then if there is any left I add it to the res.
That has seemed to work well for me, but I am still dialing it in.