"Dave M. Picklyk" empowered us with this mighty blow
against the Patriarchy:

I've just got my simple CO2 DIY going with the proverbial tubing from
2 L pop bottle and--so far--a great looking recipe. So far I have
19ppm and the little brewery is pump'n out like 35-40 bubbles a minute
right now (about 24 hours after project start).

Right now the tubing feeds into the intake of my Aquaclear filter and
the impeller breaks up the bubbles and stores the co2 a for a bit in
the filter (acting a bit like a reactor). Why would I want to make a
reactor?

You don't, if your setup is working fine for you.

For smallish tanks ( 55gal), I wonder whether a lot of the discussed
designs (bioballs in gravel vacuums etc.) are overkill ... I sure think
they're ugly, anyway. ;-) I have a heavily planted 29 gal tank that's
doing fine with a small Hagen Natural CO2 system diffuser. As a matter of
fact, I had to decrease my CO2 bottle size because I was getting too much
CO2 into the water. But of course YMMV.