ive also been messing with mine
i tried running PVC pipe to a HOB AC 300 filter, but the flow is just too much for the 300. the water flows out of the filter too fast for all the bubbles to rise to the top. it does get rid of ALOT of the bubbles, but the water level in the filter is to close to the top for comfert.
so i went back to the big ole diffuser till i figure something out.
in the diffuser i have it like this
(Bottom to top)
blue/white filter floss
tan AC 300 filter sponge
SS black sponge with hole in center
ive got the boc about 1/8in below the waterline, the SS filter about half in out of the water. and the flex pipe just barely going into the hole in the sponge.
this lets most of the bubbles rise to the top and escape, but the few that get out annoy me.
im thinking about making my own HOB fuge out of accrylic, and using the SS to pump water into it...