I have a 75 gal mixed reef with fish and a Trigger Sapphire 39 sump. I do not use any filter media in the Trigger. I drilled holes in the drain pipe in the aquarium and then wrapped it with Marineland Bonded Filter pad. I clean they pad about once per month. I use this method because I do not want to restrict the flow of and pods around the tank. I've been running this setup for a year without any issues. Any feedback or thoughts would be appreciated.