dont want to start a debate, but my understanding is that the whole reason for doing a bare bottom tank is to make it possible to direct a lot of flow along the bottom of the tank (since there is no sand), preventing any detrius from collecting, which in turn erases the need for sand-dwelling cleaners. all for the purpose of preventing the sandbed from trapping areas of abundant nutrients and releasing them into the water column without warning, resulting in loss of livestock. i do agree that the sandbed is a great asthetic addition to the tank, but this can be achieved with a sand colored bottom (starboard or acrylic sheet)
Ive seen starboard, egg crate, and PVC used in these kind of designs. Ive also seen acrylic poles used to thread on LR that had holes drilled through it. You might also want to think about a closed loop within your planned structure. Your right, the whole point of a BB tank is to increase flow without stirring the sand bed, and to decrease the amount of possible nutrients found within sand beds. This higher flow also removes detritus by allowing it to accumulate in a sump where it can be siphoned out or caught by a skimmer/s.
Yeah if you stir up the sand once in a while you could decrease the amount of air pockets and lessen the risk of having nutrient build up. I think.
Stirring the sand bed would increase nutrients trapped within it and put it into the water, and possibly raise the risk of disturbing air pockets, which shouldn't really form in a proper sand bed anyway. No matter how often you stir, chances are your sand bed will trap detritus and hence nutrients.
The thing about BB tanks Mr S., is you try to avoid nutrients being accumulated in the sand bed initially, rather than trying to remove them by stirring/siphoning, or biological means.
Its been done before, with great affect too. In smaller tanks, the lack of a sand bed would really decrease the area available for biological filtration, but with the large amounts of LR found in larger systems, going BB doesn't really have an effect.
Through my reading all over the net, this method is mainly popular with SPS keepers, who aim for the typical Low nutrient, high light, high flow, too which a sand bed can be detrimental. Their implementation depends on what type of biotope or species specific tank your going for.
Are you going SPS, Softies? Mixed reef?
