[amoreira]

I have a DSB in the tank. Downside is that it limits the amount of flow you can put in the tank. Anymore than I presently have (~ 7000 usgph), then I'd have a sand storm. The bed is shallowest at the centre of the tank at a couple of inches and at the edges it's close to 8 inches at some points. I personally like the aesthetics of a DSB in the DT. The flow I do have is adequate for the corals. I don't care about detritus transport to the sump. It can settle in calm areas of the DT where the DSB is deep. It gets processed by all the benthic fauna in the DSB. I find that BB tanks look sterile and unnatural. Shallow sand beds and BB tanks have the maintenance headache of constantly vacuuming detritus.

Let me mention that I also have:
- a lot of live rock,
- bio-pellets,
- a good skimmer
- a fuge with chaeto.
- run activated carbon (Rox 0.8 from BRS)
- run HC GFO (also from BRS)

Seems to me that all this is needed to keep nutrients at levels low enough to have healthy SPS corals (nitrates 0 and PO4 at 0.05 ppm). I think the biggest contributor in keeping P low is the GFO, with assistance from the chaeto fuge. Activated carbon keeps my water from going yellow. I don't know if the corals are negatively affected by yellow water, except for the loss of PAR as the yellow components absorb light in the UV/blue spectrum. I don't have a clue if my bio-pellets are helping. All the aforementioned are back-up to my primary filtration from the live rock/skimmer/DSB, without which I don't think my system would function at all. So, I think a multi-pronged approach is needed.