adding live sand to existing sandbed any good?????

[tyh]

Thinking of adding some live sand to my exsiting sand bed, will this be of any help? The live sand at the LFS claims to have loads of beneficial bacteria to removes nitrates( my problem) and other stuff. GUy at LFS said it's ok to add the live sand.but I've got 2 questions---

(1) Denitrifying bacteria that removes nitrates are anaerobic, hence wouldn't putting the live sand on top of my existing sand bed, a region of high oxygen content, kill such bacteria instantly rendering it useless???
Is live sand meant as the bottom layer of a DSB?

(2) live sand comes in factory packaged bags, with salt water of course. Adding such sand directly into my tank, mixing with water of different composition, e.g. salinity and so on, should cause some/lots of beneficial bacteria to die, causing a nitrate bloom in theory. Is this true?

please advise. Need to consider consequences of adding the live sand

Cheers.

 

[Anonymous]

It might not hurt too much but I wouldn't bother.. - You'd be MUCH better off getting a cup from various local reef club members.

 

[Len]

I wouldn't bother either. Anaerobes will develop fairly quickly on their own, and there really isn't a reason to seed the tank. The main purpose of seeding dead sand with live sand is to diversify life in the sand ... namely worms, bivalves, crustaceans, etc. Bacteria doesn't need much help.

 

[Unarce]

My sand bed template:

If you were to set up a reef tank with high current, than there would be a lot of bare areas if you had a SB less than an inch high. 2-3 inches is the absolute best way to go. It would be incorrect to claim that a sand bed provides 'more capacity to nitrify and denitrify' simply because it's deeper.

"As much as 70 to 90 percent of the overall denitrification was located in the uppermost centimeter. The remainder was found at 1-3 cm depth"

-T.K. Anderson 1984 "Diurnal Variations of Nitrogen Cycling in Coastal, Marine Sediments."

"anaerobic habitat can be as small as 1mm, that aerobic and anaerobic bacteria essentially coexist, and that as little as 0.08mm distance is sufficient for nitrification and denitrification to take place simultaneously."

-Ecology and Evolution in Anoxic Worlds. Oxford University Press, Fenchel, T. and B.J. Finlay. 1995.

The misunderstanding is that areas with low levels of oxygen are a must for denitrification. Since we now know that aerobic and anaerobic bacteria exist together in the upper portion of the SB, than the heavy oxygen levels of our tanks would not be a factor. It's unlikely that denitrification will occur in the deep areas of a DSB, especially if nitrates never reach it in the first place.

I'd also like to point out that a deeper sand bed doesn't necesarily equate to more biodiversity of life. A shallow sand bed of numerous grain-size will create a number of different environments housing more life than a DSB.

:wink:

 

[wade1]

Rob Toonen just did a talk at MACNA detailing a lengthy experiment contrasting plenums vs dsb and depth. Basically, anything over 1" is good. The only negative was using crushed coral at a depth of less than 1". Stay tuned to www.advancedaquarist.com for more details!

Wade

 

[Anonymous]

The nutshell answer please - Whats the negative to less than 1" CC?

 

[wade1]

reduced buffering capacity, much higher nitrogenous waste, increased livestock deaths <- hows that for nutshell?

Basically, it serves no purpose in the tank until its at a depth >1". That said, CC seems to have much higher localized phosphate concentrations as well.

Wade

 

[Anonymous]

8O

Wow.. - Higher nitrogenous waste and localized phosphate.. - Never woulda guessed actually.

Good nutshell.. - Thanx!