Or what about a Fluval 104 filter?
IDK anything about'em and they don't seem to make them anymore to read about them.
Found some parts, but that didn't tell me much.
Might make a new thread specifically for it.
Or what about a Fluval 104 filter?

i have modded most of my hot magnums return tubes...
OP asked (I think) about co2 with the hot magnum... I tried ...and within an hour the filter was gurgling and spurting...