how deep
- Thread starter rossi
- Start date
The latest study I read stated that nitrification and denitrification can take place within .08mm from eachother, so 2 inches is more than enough. It really depends on what you plan on keeping, too. You can't really say there's
one perfect depth for a sand bed.
A DSB would fit well in a lagoon themed reef. For my SPS tank, there's an average of about 1.5" of sugar-grain live aragonite under the live rock and it tapers down to less than .25" of large grain aragonite all along the perimeter. It keeps all the finer grains from flying around.
one perfect depth for a sand bed.
A DSB would fit well in a lagoon themed reef. For my SPS tank, there's an average of about 1.5" of sugar-grain live aragonite under the live rock and it tapers down to less than .25" of large grain aragonite all along the perimeter. It keeps all the finer grains from flying around.
keeping aquariums is like cars.....sure, anyone can have a car but does it run good?
and like religion....everybody has their own opinions and there are no TRUE experts....
one school of thought believes the sandbed should be at least 4 inches deep for true denitrification to occur, and also allow for more bio-diversity in the bed...there is much to research here....you can read a ton of faq's at wetwebmedia.com
but remember even they only represent 1 school of thought
and like religion....everybody has their own opinions and there are no TRUE experts....
one school of thought believes the sandbed should be at least 4 inches deep for true denitrification to occur, and also allow for more bio-diversity in the bed...there is much to research here....you can read a ton of faq's at wetwebmedia.com
but remember even they only represent 1 school of thought
Right now, there seems to be a backlash against deep sand beds with some people saying they're ticking nutrient timebombs. I've found they work very well for myself and can only offer my positive opinion on DSBs based on my personal experience. Denitrification may occur in beds as shallow as an inch, but taking an oxygen meter, you'll find it's usually not the case in our heavily oxygen-saturated reef tanks. Deeper sand beds inherently have more capacity to nitrify and denitrify based on sheer area of habitation alone. And it's also supports more biodiversity. That's why I still prefer sandbeds greater then 3" in depth.
Your mileage may vary
Your mileage may vary
I vote for the DSB. One solution to the "old tank syndrome" if you feel it is tied to the DSB is to remove portions of the DSB and replace with fresh sand. the new sand will be populated quite quickly from the existing bed. Siphoning out 10% every now and then could do it (when the tank is over 5 years). Another solution would be to take out that 10% and rinse it with new salt water as you might with fresh sand......original suggestion from Bob Stark - ESV
I didn't get the "slap in the face" either.
If I were single, I'd take you up on that SPANKING, seamaiden.
DK described what is sometimes missed for proper maintainance of a DSB. Although there's no direct evidence that a DSB leads to OTS, phosphate leaks, etc. I'm sure it has helped him avoid these troubles.
DSB's certainly have their place, but would like to help rossi understand the difference. If you're looking to increase biodiversity in a sand bed, than the deeper the better, but 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."
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.
If I were single, I'd take you up on that SPANKING, seamaiden.
DK described what is sometimes missed for proper maintainance of a DSB. Although there's no direct evidence that a DSB leads to OTS, phosphate leaks, etc. I'm sure it has helped him avoid these troubles.
DSB's certainly have their place, but would like to help rossi understand the difference. If you're looking to increase biodiversity in a sand bed, than the deeper the better, but 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."
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.
Without taking sides on which works better, deep or shallow sand beds, there's one other factor that must be considered. Deep sand beds look like crap when viewing the tank from the front or sides. Algae grows between the sand and glass. Filth collects in the viewing area, and greatly distracts from the beauty of the rest of the tank.
When the bottom 4"-6" of the tank is nothing but dirty, algae ridden sand, that's the first thing people notice. I for one don't think that the benefits, if there even are any, of a DSB is woth it.
BTW, my tank is in a formal living room, where appearance is of the utmost importance.
When the bottom 4"-6" of the tank is nothing but dirty, algae ridden sand, that's the first thing people notice. I for one don't think that the benefits, if there even are any, of a DSB is woth it.
BTW, my tank is in a formal living room, where appearance is of the utmost importance.
I can't imagine a 6" piece of wood around the bottom of the tank looking good either, even if you could get it to match the stand.
I like tall tanks. I'm not going to waste 6" of height just for sand. Like I said, IMO, it's just not worth the trouble.
I like tall tanks. I'm not going to waste 6" of height just for sand. Like I said, IMO, it's just not worth the trouble.
Aside from the fact that their biggest expert and proponent is an idiot and a liar:
http://reefcentral.com/forums/showthrea ... did=257196
http://www.thereeftank.com/forums/showt ... adid=23293
http://www.thereeftank.com/forums/showt ... adid=24955
http://reefcentral.com/forums/showthrea ... did=210605
http://reefcentral.com/forums/showthrea ... did=251077
http://reefcentral.com/forums/showthrea ... did=257196
http://www.thereeftank.com/forums/showt ... adid=23293
http://www.thereeftank.com/forums/showt ... adid=24955
http://reefcentral.com/forums/showthrea ... did=210605
http://reefcentral.com/forums/showthrea ... did=251077
With all the moving I have done over the past 10 years I've now had the opportunity to try several different types of systems. Personally, I've not had any nitrate problems with any of them - barebottom, very little substrate, about 1" of sand and a 5" DSB.
I've gone in a big circle and I'm back to a barebottom setup after my last move. I don't particularly like the look (not that bad actually, once it's all encrusted with stuff) as much as sand, but it makes maintenance really easy and it's really nice to have lots and lots of flow without having sand blowing around. It's amazing how much detritus comes off the rocks every week with a turkey baster and I just don't have a lot of confidence that my sandbed could "process" all of that stuff. I prefer to remove it manually (ie. syphon it out with a small water change each week).
One of the biggest arguments for a DSB is its denitrifying capabilities. Personally, I've not had a big nitrate problem with or without a DSB, so I don't really see that as a huge advantage in my case. I know they work well for some, but I don't think I'll bother with them in the future.
IMO there are many ways to be successful in this hobby. I think it just boils down to what you're comfortable with, what you want to do for maintenance, what sort of critters you want to keep, etc.
JME/JMO...
I've gone in a big circle and I'm back to a barebottom setup after my last move.
I don't particularly like the look (not that bad actually, once it's all encrusted with stuff) as much as sand, but it makes maintenance really easy and it's really nice to have lots and lots of flow without having sand blowing around. It's amazing how much detritus comes off the rocks every week with a turkey baster and I just don't have a lot of confidence that my sandbed could "process" all of that stuff. I prefer to remove it manually (ie. syphon it out with a small water change each week). One of the biggest arguments for a DSB is its denitrifying capabilities. Personally, I've not had a big nitrate problem with or without a DSB, so I don't really see that as a huge advantage in my case. I know they work well for some, but I don't think I'll bother with them in the future.
IMO there are many ways to be successful in this hobby. I think it just boils down to what you're comfortable with, what you want to do for maintenance, what sort of critters you want to keep, etc.
JME/JMO...
ChrisRD,
I favored BB tanks in the past when I used to keep soft corals. It eventually turns out looking natural with coralline, mushrooms, polyps and so on.
I do wonder how much an effect it is to have light reflected back up from a sand bed. After all, it is brighter than BB. Ever since I went SPS, I had considerably more growth with a thin layer of sand compared to BB.
Have you noticed any difference in growth?
I favored BB tanks in the past when I used to keep soft corals. It eventually turns out looking natural with coralline, mushrooms, polyps and so on.
I do wonder how much an effect it is to have light reflected back up from a sand bed. After all, it is brighter than BB. Ever since I went SPS, I had considerably more growth with a thin layer of sand compared to BB.
Have you noticed any difference in growth?
Not really in my case, but the tank is a mixed reef and I've got the SPS at the very top.
I could certainly believe in the case of a system where high light corals will be at the middle and lower areas of the tank that the extra reflection of the white sand would help.
Good point.
I could certainly believe in the case of a system where high light corals will be at the middle and lower areas of the tank that the extra reflection of the white sand would help.
Good point.
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