Greg, I just read your article on sumps. I just picked up a 90 gal. tank that has a tidepool sump with it. In your article you mention that bio-media should no be used with a reef setup. What "stuff" should I be using? Is crushed coral a viable media? What particular material should I be considering? There are four separate media trays, a bio-wheel, and a large open area for pump, heater and skimmer installation. I'd like to use all areas for various media only because I'm obsessive! Any recommendations would be greatly appreciated.