The vast supply of carbonates helps to bind the PO4 up along with surface to air area . Never confuse a little glass box of saltwater with a ocean. Not to mention as Aqua Boy mentioned all the mangrove swamps and mud marshes that are around the world. And some is used by some animals I'm sure Like the Methane's from the thermal vents .. But I'd not try to bubble pure methanes into my tank.. More cooler fresh sea water laden with oxygen passes over a reef per night then all us here combined would ever use or change out in several of lifetimes ..
But look at the Chesapeake Bay PO4's and NO3's about killed it over the last 30 yrs alga's where chocking out all life forms. Hence the Bay act of the 80's The Chesapeak bay is just a huge aquairum (: Its comming back but it took billions upon billions and many law's and stiff penalities to prevent over building and ground run off and water shed area. And that water in Maine has been around the world in the last several thousand yrs.. here today gone tonight _________ Some of the world's greatest feats were accomplished by people not smart enough to know they were impossible (Doug Larson) |