Doubling my skimmer or not

[The Grizz]

Doubling your volume is a myth that I feel was thought up by retailers & there is such a thing as over skimming. Skimmers work on what is called contact time, the more air volume introduced to the water the better it will it will pull the skimmate out. A skimmer that is rated for 300 gals is more then enough. As for a recirculating skimmer that would depend on if you have the room as most are external. Loook at the air volume per liter as well as what the skimmer is rated for.