nano DSB's

[phenom5]

hello,
there's a pretty hot BB vs DSB vs SSB debate over on NR. i thought i read somewhere that a DSB needed to be a certain size (footprint, not depth) to truely be effective. i cannot find any info, so now i'm wondering if there is any truth to that. for example, would a DSB in a tank with a 20"x10" footprint be effective?
TIA

[rshimek]

Hi,

A sand bed of that size would be effective at looking like a layer of sand. That is pretty much it.

I don't consider that a true DSB can be set up in a tank with less about 4 square feet of footprint.

[phenom5]

hey thanks...i knew i read that somewhere, but i couldn't find it.

[Fissy]

Hi Ron,
What do you mean by "effective" ? Wouldn't the bio-load to sand bed capacity remain proportional to the tank size ? In other words, if you have 4 lbs. of bio-load in a 4 sq.ft. live sand bed and 1 lb. of bio-load in a 1 sq.ft. live sand bed, wouldn't the net result be the same ? Does one amphipod do better in 4 sq.ft. of sand rather than 1 sq.ft. ? Why ?
Thanks.

[greenbean36191]

[welcome]
I can't get the search to work right now, so I can't dig up the old thread where Dr. Ron talks about this, but the problem is "the edge effect." A lot of the worms and other life that make DSBs work avoid hard surfaces such as the edges of your tank of LR. As you shrink the surface area of the sandbed, the area these animals avoid grows in proportion to the area they will go. The tank may have a square foot of total area, but only 3 square inches where the animals live and breed. That's ok for some of the animals, but others need much larger areas to create self sustaining populations.

The bioload of the tank will shrink proportionally to the tank, but the filtering capacity of the DSB only shrinks to a certain critical mass, at which is just stops working like it should.

[Daemonfly]

I've been mentioning this to everyone who asks about DSBs in nanos over on NanoReef. Some people even try to do DSBs in Aquaclear 500 filters that we convert to refugiums.

[rshimek]

Hi

[thanks] to Mike for the good answer. Nothing more to add.