I'd take the 3d printed over foam, not a fan of any foam or anything that collects detritus.
Just turn down flow on intro and a day or so, not all the time.
It does sound kind of odd as yes, usually this is only an issue w/ weak fish, so something is amiss, maybe post pics if you can.
There's a fine line between owning your tank, and having your tank own you!_________________________________________
120G SCA starfire, tunze 1073.02 return pump, Geisemann reflexx 4xT5, 2x panorama pro LED strips, 2x Vortech MP 20's, 40g sump w/ fuge.