It a hang on the back Petco Power Filter 30. It came with the used tank setup. I pull off the old filter floss and replace the spent charcoal with Amo-Carb (activated charcoal with Amo-Lock). Then I cover the charcoal with new floss that I hot-glue to the filter plastic filter cartridge. The final step is to rinse it thoroughly to remove all charcoal powder. -----Original Message----- From: gsas-member-bounces@thekrib.com [mailto:gsas-member-bounces@thekrib.com] On Behalf Of Doerr, Jesse Sent: Wednesday, November 05, 2008 9:05 PM To: Greater Seattle Aquarium Society member chat Subject: Re: [GSAS-Member] Thoughts on tank clarification? Tom, >> I do a 10% water change once a week and make my own filter cartridges >> that I change at water change time. What kind of filter are you using? Jesse Doerr _______________________________________________ GSAS-Member mailing list GSAS-Member@thekrib.com http://lists.thekrib.com/mailman/listinfo/gsas-member _______________________________________________ GSAS-Member mailing list GSAS-Member@thekrib.com http://lists.thekrib.com/mailman/listinfo/gsas-member