The cheap CO2 Atomizer (external inline ceramic misting, search ebay for it) is an incredible CO2 bomb machine. Anyone should give it a try
Sadely, I never could compare it to my external AM1000 on my 230L as I stopped the tank before I start the experiment. Based on what I see in my 12 gal + people reports, coupled with a powerful filter, it will beat most CO2 systems + absolute silence