Yea and bacteria works best attached, not floating
around in the water, therefore the plenum provides
less space for bacteria to grow.

Wayne Sallee
Wayne's Pets


Pszemol wrote on 3/2/2007 11:06 AM:
"KurtG" wrote in message
...
Pszemol wrote:
"KurtG" wrote in message
...
Pszemol wrote:
Plenum is an empty space UNDER the sand, so I am not sure
how can you understand the advice on vacuuming it...

Apologies. I'm reading a book that appears to substitute Plenum for
sand as it doesn't want to confuse the reader with silica sand.

What book is it?


The Reef Aquarium: Science, Art, and Technology, Vol. 3
by Julian Sprung (Author), J. Charles Delbeek (Author)

I'm about 300 pages into this weighty tome. Perhaps I was
misunderstanding, but they seemed to refer to the sand bed as the plenum.

My understanding of a plenum in reef tanks is different.

Plenum method is based on a empty space under the sand
isolated from the sand with a layer of plastic mesh streched
over a construction of PVC pipes frame...
The idea is that the water accumulated under the sand is
anoxic and behaves as nitrates processing bed...

This idea is controversial, since water deep in the sand layer
without plenum will be anoxic too... so there is really no
reason behind building this artificial empty space under the
sand just to get anoxic layer of water...

I do not know how popular the plenum method is, but
I would not assume everybody here have plenum in
their tanks, nor suggesting vacuuming plenum makes
any sense at all...