Amphiprionocellaris
New member
It doesn't work that way man..... You don't have hundreds of thousands of tiny mouths in the sand bed just waiting for you to feed the tank. They are sustaining themselves on the nutrients you added yesterday, last week, or even months ago.
It very much works that way; a healthy sand bed quickly consumes organic material, rather than acting as some sort of sponge that accumulates reactive matter, as is often stated about them. Why does it matter when a particular nutrient was added relative to when it was consumed? If the system is stable and mature, the net growth of free nutrients is zero regardless of residence time. If you want to argue that the biomass itself is an accumulation of nutrients, which some have wanted to do, then fine but again at maturity that biomass is not necessarily increasing.
But it doesn't "manage nutrients" the way many people believe it does. The whole DSB method is a way of holding nutrients within the system, increasing the nutrient content of the system, making the system more dirty, not more clean, making the system less hospitable to higher and more environmentally sensitive forms of life.
Why do you say these things, what is your evidence? Based on benthic ecology I can confidently say that sand beds *do* manage nutrients by both removing nitrogen into nitrogen gas and breaking large organic molecules into forms that leave the sand bed for scavenging or removal via biological uptake (e.g. By corals and zooxanthellae) or filtration. Coupled with aggressive filtration methods and a large population of corals, clams, etc, it is very easy to maintain both N and P well below the threshold levels for reef health, as well as maintain very rapid rates of growth. Nowhere does the system get "more dirty"; mine has crystal clear water and no algae. Nothing in that equation makes the system hospitable to higher life; indeed based on the relationships between energy flow and diversity, there is also a good argument to be made that in some ways the rapid nutrient cycling makes it more hospitable than without.
None of this is based on opinion; it's based on 20 years' experience involving hundreds of personal and commercial tanks, plus - more importantly - known science about sediment/benthic ecology from the primary literature and my own research. I would be happy to provide the dozens of papers specifically on this topic that have led me to my conclusions; they may be behind a paywall but usually the abstracts are open access.
