I have the Fluval P2 protein skimmer which is designed to fit into the first chamber of a Fluval EVO 13.5 all in one. The skimmer would work in other nano tanks as well. I used this skimmer for about 3 weeks, however; I upgraded my filter baskets and no longer need this.
$20 or will trade for a coral frag. Located in Centerville / Washington Township