deep sand bed

So I would like to have a discussion about denitrification regarding its understanding and what aspects are imperative. First off anyone replying to this thread understands denitrification is the conversion of nitrate to nitrogen gas through having a deep substrate that creates anoxic (No O2)...

I've recently been spending a lot of time researching saltwater reef systems. In a reef tank it is general practice to have a sump with a refugium. Often times the main display tank or the refugium will have a deep sand bed of 4+ inches for the purposes of denitrification. If one were to...

Ok, I know lots of people freak out and worry about a deep substrate going annoxic ==> releasing hydrogen Sulfide (HS2) into the water ==> Dead fish. But then others say deep beds are the greatest thing ever and it will help your tank...