Substrate Type and Depth?

[SmCaudata]

I currently have about 10lbs of sand (think it is Aragonite) and 10 lbs of crushed coral in the bottom of my 20H. I have about 5lbs of sand in my 10gallon that will be moved over once this new one is done cycling.

 

Currently the substrate is very coarse. It seems that the fine sand just settled to the bottom and it looks just like crushed coral. I had heard of people doing 50/50, but now I am wondering if I should have gone all sand. Is it bad to have a coarser, sort of rocky substrate? There is some sand there so it is not pure coral.

 

Second question is the depth. It is currently about 1.5" deep throughout the tank. Do I need more? I have seen people going both ways (SSB and DSB). What exactly are the advantages to either? I have a 10lb bag of "live sand" here. If I don't need it though I think I will bring it back. I like the way the gravel looks now, but I am not sure if I should have a softer substrate.

 

Thanks.

[EtOH_is_good]

can always test to see if argonite by using the viager test. argonite rocs will fizz. larger chunks will always migrate to the top. course or fine corals dont care. look is a matter of asthetics. if you have a sifter fish, definately want more fine stuff. can't really do a good dsb in a nano because it just takes up too much space. 1-2" is good depth. if you already have sand from a cycled tank, then probably enough live sand. adding the live sand for more volume wont hurt, but live or dead it wouldn't matter with a shallow bed. you just need to decide which look you're going for.

[SmCaudata]

I have a yellow watchman, but he is currently in a soft sand tank and I never see him sift through his gills. He just picks fallen flakes off of the top.

 

Is aragonite important? Crushed coral should have the same type of buffering capacity right?

 

I have a 20H, so the sand bed depth really won't be too bad even if it is deep.

[EtOH_is_good]

benefits of a dsb are debateable (see reefcentral). water changes are going to be the best way to get rid of nitrates and getting the biodiversity in a nano tank is plain hard. yes, i believe that crushed coral will have the same buffering capacity. hopefully someone corrects me if im wrong. nalbar?