DSB Dynamics- To use or loose?
 

Wanted to start a discussion on the use of DSB's and remote DSB's in reef tanks and how they work for everyone. Are you running one, how large and deep is it, what's it composed of, who lives in there, how much flow is in it, how did you seed it, is it dark/ light and the most important question "Do you think it works?".

I'm currently running two but I can't really consider either of them anaerobic. The first is a 30g fuge with a 6-8 inch bed, this tank is full of mangroves and a pistol shrimp/ goby pair which would eliminate any anaerobic areas. The second is about 12X12X10 inches of sand in the return area from my main tank, excuse my paint skills but here's a basic drawing:

http://img63.imageshack.us/img63/3240/deepsandbed.png

So water comes from the main tank and is injected under the sand, the process looks really close to a phosban reactor just with allot more flying media.

30g Fuge/ DSB
Seeded from old tank sand
Pistol Shrimp/ Goby pair and a ton of mangroves/ cheato live there
Sand is aragonite mixed with rubble and reef mud
appx 5X turn over per hour through the fuge
Lighted for 12 hours per day

29 Sump/ DSB
Seeded from old tank sand
No fish, TONES of feather dusters and macro inverts
Sand is aragonite and larger gravel pieces
Appx 60X turn over through the sump
Non-lighted

I have a feeling my almost non existent cycle (and my lack of pest algae) in my new 170g is because the transfer of 2 established DSB's from my old systems to the new one. Since adding them I have seen my water quality improve (Reduction of Nitrate, Nitrate and PO4) and a dramatic increase in the ability to successfully keep different species of cnidarians/ fish.

you arent going to get the same effect with the water going up through the sand. you need to have no oxygen in the bottom for anarobic to work you are just going to have the sand all over the place.

I've been DSB free for a few years now and never looked back. I still get envious of those with nice white sandbeds but all mine ever did was collect detritus and create a nutrient sink for algae growth.

Well the sand does fly all over the place but a decrease in anaerobic bacteria would yield an increase in aerobic bacteria (Atleast this is my approach at it). Does anyone have any studies cited on the efficiency of anaerobic compaired to aerobic in respects to nutrient export? I would think that the presense of oxygen would increase efficency (Atleast in Eukaryotes this is true) but could be the opposit for prokaryotes.

Christy have you ever tried a remote DSB? My main tank only has about 1-2 inches of sand but I reap all the rewards of a DSB by having them out of the display.

BB here and liking it. No problems with algea, nitrates etc so thinking a DSB not really required other than for looks.

As for a BB staying bare, gets cover with coraline and corals so not that noticeable after a while.

See here for a GSP bottomed tank

I run one on my 100 5-6 inch deep slow flow but I have a power head in there to keep strong flow if that makes sense lighted two T5 with 5000k bulbs and I have a few sand snails. I have some really cool feather worms and other stuff in there that is doing really well. Mine is remote so I can shut it down at anytime. So far it is still all white no dead spots. No No3 but then I don't have any in my BB tank either.

To be honest, I've never really known the "benefits" of a sandbed. Once I started experiencing success without it, I never really found the need for a remote DSB.

I like my dsb. I have it in my display tank and I have no problem with nitrates. I like the look and it doesnt limit me on my livestock. ie - some wrasses and such that burrow into the sandbed at night.

I do get some algae on the sandbed but it is kept under control with a sanddollar and cucmber.

For those of you who are BB, do you have to vaccumm the detrius off the bottom and how often?

DSB does work, the problem is that it will crash the tank eventually sooner or later.
BB is way safer especially when you have large amounts of live rock.


Though in smaller tanks (less then 100 gal) it makes sense to have a shallow sand bed an inch or so it will accumulate detritus , however it will also make tank more stable.

This is an age old question that we could discuss until we are blue in the face, but to say that ALL DSB will Crash ALL tanks at one time needs some revamping. I have a feeling that people who have a crash at the 2-3 year mark with no apparent cause automatically blame it on "Old tank syndrome" and there deep sand bed because as humans we need to classify our failure. Anyone have any reading on how a DSB works over time, I would enjoy some brief info on this.