[Delphinus]

(Baaaahhhh humbug.)

One point to consider, or at least my little modicum of knowledge that I want to throw out into this, is that particle size of a sandbed directly correlates to what kinds of infauna it will support over the longer term.

For example, I have a 20g tank with a 4" sandbed in a 10g sump. The particle size is too large for what we would consider a "proper" DSB. In fact, as DSB's go with denitrifying (or whatever the term is), it's useless. The bed is three years old and has yet to develop any anoxic zones. BUT, the reason I don't pull it out, is that it is a perfect breeding ground for larger 'pod type infauna. My 20g is literally white with bugs at night. Of course, of great significance to this that I'm obligated to share (to provide both sides of the story), is that since there are no fish in this tank, there is a limited number of predators for those bugs and that's probably a contributing factor to the overall numbers, but, I'm convinced that the larger particle size is a key factor in this case as well.

The oldest sandbed I ever had was 5 years, but again, it would not be considered a "true DSB" because of the particle size. This was also a plenum'ed tank, and over 5 years I sure saw some pluses and minuses with that type of setup. When I had set up that tank plenums were still "in vogue." Shortly thereafter, they were no longer fashionable and DSB's were all the rage.

Fashions come and fashions go. Some ideas have merit, but rarely do ideas come that are only merits without some kind of pitfall. Sometimes the pitfalls aren't seen until you're well knee-deep in it.

Interesting thoughts though. I guess when I set up my 50000 gallon tank one day, I won't have to spend $200g on the sand after all. Maybe only $10g. That's a releif!!!!!