Is fine white sand good for DSB in fuge?

[wojo]

i posted this few days back in Reef Discussion but didnt get much attention, trying my luck over here ;)

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I have about an inch of sand in my fuge and im considering adding more to make it DSB to get my nitratres down. Is fine white marine sand good for this purpose? i mean can i add more sand on top my the current one without causing problems?

Also is 3" enough or should i do deeper?

Thanks...

[Waylander]

I think the 'pros' say that you should add sand 1/4" at a time to minimize damage to the aerobic/anaerobic areas. They, also say, more than 3" or less than 1" .
That said...I am not a pro. I dump what I think that I need in one corner (or several areas in larger tanks) and let it self level over time. Given that you will dissolve 1" of aragonite (I assume that you are talking aragonite and not silica) per year, I would go ahead and try for 4"+ in depth. I like the fine sand in refugiums.

Of course, you realize that there are the BB gurus out the that believe that the only use for sand is for Chuck Norris to kick in the eyes of bad guys before shooting them 87 times with his sixgun and making off with the beautiful woman?

[wojo]

so fine sand will well for DSB in fuge?

[rustybucket145]

yes sand will do fine for a DSB in a fuge. I woud push the existing sand over to one edge, fill up the semi-bare side then push your old sand on top of the sand you just put in. Then fill the other side. Several studies have been done on DSB with varying results. The overall consensus is that the sand needs to be (at a minimum) 4" but the majority of reefers (myself included) have over 6". Good luck!!

In my DSB's in addition to sand I also have some aragonite and various size sea shells mixed in with it to give it a more natural feel.

[jpfelix]

a lil' rubble is good for hosting little pod proms.

[jasonkola]

I have been wandering tyhe same thing myself. I have been researching it a ltttle and got alot of different opinions. I read one book that said the ideal size for a deep sand bed with a plenum was between 1 and 4 mm size with 2 to 3 being prefered to allow big enough partical size to allow good diffusion down through the sand for denitration. the same book said a size of smaller than 1 mm would be good as it would be so fine it would not allow sufficiant water diffusion down through the sand for denitrification. then I read another artical that said the fine sand was better as it had more surface aria for bacteria and would be so fine that it would help keep waste products from sinking into the sand and becoming a nutrient sink. I can see the valad points of both. I think it would be ok to have a fine bed about 1/2 inch or so of fine sand on top of a coarser sand to filter out the tank wastes from sinking down in the sand bed. you would have to seperate the sand layers with screen material to keep it from mixing down into the coarser sand. then if you had animals that needed to burrow deep the half inch layer on top wouldn't be enough. and the screen would stop them from going any deeper. so I am still undesided on how I plan to setting up the sand bed. I am leaning tword forgetting the fine sand and haveing a bed of special select grain size of 1 to 2 mm of argonite. I have a bunch of the fine stuff I purchased on sale but I am not sure I am even going to use it. oh well.