Sand bed thoughts

[christyf5]

I'll admit it. I'm a sheep. I first started my tank with a plenum because it sounded good at the time. When I moved up to a larger tank I was told a 4" DSB was the way to go. I guess I just go by the experiences of other people and nobody I talked to at the time had a bare bottomed tank. I kind of like the added glow of the white (well pseudo white in my case) sandbed. I also think it provides a home for a host of critters that wouldn't necessarily be around if I didn't have the sandbed. I also think that the DSB really should be recharged (or at least charged) with new critters (ie. sand exchanges from other tanks) fairly often. I would think that the critters in your tank can't necessarily handle ALL the detritus that the DSB receives.

Does anyone know exactly HOW the DSB becomes a sink for all the heavy metals and such (chemically I mean)?

When you say the DSB becomes exhausted after a few years, what exactly does that mean? What about it becomes exhausted?

Christy