Save me... I'm thinking of doing a plenum...

Oh and I don't think you should stir up your sand bed at all.  I don't know how mixing up the aerobic and anaerobic zones would be beneficial to the bed.

I am not sure, I just know that my coral would all close and emit the stringy spideweb like emission that made me think they hated it, but that's just me.

Huh.

I just can't go willy nilly, Tim.

To be fair I quickly glanced through most of the above posts, but I though I would offer a few more clarifications/thoughts.

• I do think you should stir your sand bed (no matter if it has a plenum under it or nor), but I should be more clear on what I mean.  I only stir the very top of the sand bed (maybe the top 1/2"-3/4").  This not only feeds your corals/sponges/worms etc., but keeps the top of the bed looking nice.
• Just for the record I will not make fun of you if you add a plenum (at least not to your face  )
• OFF-TOPIC: I have run many tanks without a sump.  I think having a sump is better, but I would not hesitate to setup a tank without one.

Edited by Jake Pehrson - April 03 2008 at 4:04pm

GARFVolunteer wrote: I am some dumb hick that grew up in a town with a population of 211.  I have some college but not a lot.  This is what I know which contains no scientific fact...   I would do a DSB in a heart beat because they look nice.  Then I would place a plenum remotely in the sump.  The only down side to a plenum is they are ugly...     Thanks,   Scott

I thought of another reason it doesn't matter if you do a plenum or a DSB.

We run shallow sandbeds and barebottom, 
I'm guessing this whole debate is over the removal of nitrates,

As mentioned there are several opportunities for problems with deep sand beds, possibly Hydrogen sulfide problems, etc,

I think there are several much easier ways to export nitrates, ie water changes and refugiums, and efficient protein skimming

Most people are using/doing all of these

So why such a debate over the use of deep sand beds and plenums if they are just redundant filtration for what you are already doing?

In our barebottom tank we run a remote refugium with a ~4" sandbed, deep enough or large enough for effective nitrate removal? probably not but it does provide a nice place for pod production

I'm not sure what is referred to as expensive equipment for bare bottom tanks, just a good skimmer as most have anyway,
Shallow sandbeds provide the aesthetics of sand, Ph buffering (debatable) and micro/macrofauna production without any of the other hassles.....

Just trying to see the rationale behind these,
As far as I've known they were the rage before the advent of efficient skimming, which makes sense in that era, but I think it is pretty redundant in our current systems

GARFVolunteer wrote: carlso63 wrote:   OK - sidebar  - am I doing something "unique" because once set up you can't see my plenums... but yet everyone else keeps referring to how "ugly" they are...?   OK maybe ugly is a harsh word... I should have used less beautiful... or plain when compared to the pristine white of a DSB...   If I am building the stand for a plenum system, I will design it to hide the substrate like I did with my current setup.    The first plenum I ever remeber seeing was Sally Jo's tank which is over 13 year now.  Awesome tank if you look at the top 5 to 7 inches...  I guess the ugliness of the bottom really made the top POP!   Thanks,   Scott

Again I am going to start out saying that I only skimmed the above posts.

Isn't the main reason for having a DSB or plenum to provide a denitrification area?

If so, this requires that the sand bed maintains an anoxic (anaerobic) area for denitrification to take place.  Yes it is possible that you may also create hydrogen sulfide, but I have really never seen HS cause a problem in an aquarium (even when the sand bed has been greatly disturbed).