Opinions on how to construct a DSB?

[lakedawgs]

I am getting ready to setup a refugium for my 15g reef. I have been reading alot lately and there is a great deal of differing opinions. Most of what I have read on the boards says to lay down your oolitic dead sand and put live sand on top of it, but I was reading 'the guide to successful substrates' at www.inlandaquatics.com site which says to put down piles of live sand on the ends of the tank and put oolitic dead sand on top of them. What are you folks opinions on this?
thanks,
lakedawgs

[the_blue_tuna]

In my opinion , you are better off laying down your bed of dead sand , then seeding it with live sand and/or a detrivore kit. My concern with covering your live sand is that some of your fauna may not be able to make it back up to the surface . Worms would not be as big a problem as say pods.

[SPasse]

lakedawgs,

Here are my three “recipes” in order of preference:

#1 60% ESV “Fine Grade Oolitic” (<0.5mm) Product #140 (50lb Bucket) ESV ships direct.
30% CaribSea Oolitic Select, product #932 (~0.5mm) (30 lb Bag)(This was formerly called “Sugar Size Select”
10% CaribSea “Sea Flor Special Grade Reef Sand” (~2.0mm)Product #50 (44lb Bag)

#2 90% SouthDown Tropical Play Sand For The Caribbean”
10% CaribSea “Sea Flor Special Grade Reef Sand” (~2.0mm)Product #50 (44lb Bag)

#3 100% SouthDown Tropical Play Sand For The Caribbean”

#4 100% Aragamax Grand Bahama Sand Product # 931 (30lb Bag)

Depth of the sand should be 4 to 6”. (6” is even better, and will have more de-nitrating capacity.)

The practical difference between 1,2 & 3 is small. #4 is probably alright too.

You need just a few pounds of live sand(s) as a seed culture(s). The sand bed should be seeded with as many different sources of live sand as is practical for you. I used live sand starter kit from Indo Pacific Sea Farms, Island Aquatics, and two local sources. Bio-diversity is a good thing. Then you begin feeding the bed and the fauna community that it contains grows into a complete ecosystem that is uniquely suited to you particular tank environment.

But make it as deep as you can, I attribute much of my systems low nitrate (<0.2ppm) to my 6” DSB

The bottom line is that:

1 Course sands are not conducive to supporting the proper sand bed fauna community.

2 Course sands tend to become a detritus trap with time, this is related to #1 above also.

3 A deep fine bed is necessary to create the required anoxic conditions for efficient de-nitrification.

Regards,

Scott

[cod]

Howdy Lakedawgs:
The sand bed in my refugium is about 4.5" deep, with 3" aragonite (1-2mm.) and ~1.5" shell frags/reef rubble. The shell/rubble is on top of the arag. I also have about 10lbs. LR. This setup has been running like this for about 8mos. at 0 nitrate.

I haven't noticed detritus build up, probably thanks to hermits that have outgrown the display tank, and a healthy population of detritivors!

FWIW I read the instructions for building a DSB at the I.A. site, and I think they recomend burying the LS to preserve the denitrifying bacteria. But IME, if you create an anoxic/anaerobic area the bacteria will appear the same way nitrifying bacteria do.

Later! Mike