Has anyone here ever used an ECOAQUALIZER? It supposedly reduces water changes and enhances your fishes health/immune system. I know one person who has it and they swear by it. This person has a 300+ tank full of large angels, tangs, etc and claims his tank overall is doing much bettor after installing an ecoaqualizer.
http://www.ecoaqualizer.com/products.htm
http://www.ecoaqualizer.com/products.htm