Deep sand Bed height

[j-man]

If you use a larger size arragonite,
How deep is sufficent to create
micoaerobic bacteria to convert NO3 to
N2, O2, and not anaerobic. I don't want Hydrogen sulfide in my tank!

 

[nacl-h2o]

If you use aragonite, I believe 4"-5", but that depends on just how larg is what your calling larg?

 

[fshhub]

smaller grains, and definitley not larger grain(like cc), and 4 to 6 inches, if you use cc or crushed aragonite, you need a very deep bed, the smaller particles are better, IMO, and using smaller grain could mean less, whereas the larger grain could mena you need more for the same benefits and efficiency
HTH

 

[beth]

IMO, the "Hydrogen sulfide" issue is way over rated. If you setup a proper DSB, this should not be an issue. Variable grain sizes is what is needed ranging from .02-1.7.
The minimum bed should be no less than 4" but 6 is better. I have 6" dsb started in Dec and have not had nitrates yet. I used 3 different sources of sand with varying grain sizes.