There is some controversy as to the efficiency of airstones versus the conventional powerhead system. Arguments can be made in favor of both systems, and both possess certain advantages and disadvantages. Among aquarists, the choice is very much a matter of personal preference, although the question is sometimes a shibboleth in Internet discussions.
- http://www.marineandreef.com/shoppro/protein_skimmers_Airstone.html -- Website of an aquarium supplier
- http://www.thekrib.com/Plants/CO2/airstone.html -- Information on the airstone controversy