The cost was one of my big problems when I first looked into building a Charcoal Filter/Scrubber.
But, prices have dropped a lot since than and Walmart has some cheap bags of Activated Charcoal for aquariums.
Just trying to figure out what type of design to use.
I just got my Ozone Generator the way I want it (It’s a good thing that the parts are now readily available and I did have to build the glass panel sandwiched between metal screens powered buy a Neon Transformer.).