a_fender69
Member
I am a critic of Deep Sand Beds. For those who support them, please tell me why and the benefits with solid evidence if possible, or articles that support your veiws and theories.
Critic of DSB
- Thread starter a_fender69
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j21kickster
Active Member
tell me why you are denying their effectiveness and i'll tell you why they are good-do you have evidence that says they are bad- or did you just one day think - Ya know, I think the DSB theory is a crock?
a_fender69
Member
No I didn't have a dream about DSB as the boogie man, here is what my thought is.
In tanks with a DSB, there is not a constant circulation of the sand, no matter what kind of stars, fish, or crabs you may have.
As this occurs, mind you not over night, anarobic bacteria builds up in the middle and lower layers of the dsb.
Evidence, why is it not smart to stir the dsb, because you are releasing this bacteria in the open water. If it were down on a regular even hourly basis, then no objections, but who can maintain that?
Second, like deep crushed coral beds, when stir their is an increase in nitrates and nitrites.
I have tested my theories, you try.
Take a water sample from the top of the tank, open water. If you have a good tank, you will have good water.
Now, stir up the bed all the way to the bottom, with the syringe, draw the water and test again.
try this many times and check results.
You may be suprised if you have the same results that I have had.
In tanks with a DSB, there is not a constant circulation of the sand, no matter what kind of stars, fish, or crabs you may have.
As this occurs, mind you not over night, anarobic bacteria builds up in the middle and lower layers of the dsb.
Evidence, why is it not smart to stir the dsb, because you are releasing this bacteria in the open water. If it were down on a regular even hourly basis, then no objections, but who can maintain that?
Second, like deep crushed coral beds, when stir their is an increase in nitrates and nitrites.
I have tested my theories, you try.
Take a water sample from the top of the tank, open water. If you have a good tank, you will have good water.
Now, stir up the bed all the way to the bottom, with the syringe, draw the water and test again.
try this many times and check results.
You may be suprised if you have the same results that I have had.
j21kickster
Active Member
the point is to have anerobic areas in the bed- and alsothat testing method holds no significance to your argument b/c unless you are always stirring up the DSB there would be no problem ( that would be expected to happen since there is organic build up- weather it be in a DSB or CC)- also a DSB supports a greater diversity of life than a thin layer of CC- so far, im not convinced
bang guy
Moderator
This is a good article from a scientists point of view:
http://www.rshimek.com/reef/sediment.htm
In addition, I have personally witnessed Nitrate levels fall from high levels to low levels after incorporating a DSB. My main purpose for a DSB is the Zooplankton released from the bed.
http://www.rshimek.com/reef/sediment.htm
In addition, I have personally witnessed Nitrate levels fall from high levels to low levels after incorporating a DSB. My main purpose for a DSB is the Zooplankton released from the bed.
broncofish
Active Member
Bob Fenner writes a ton of stuff on DSB's wet web media, and I'm pretty sure everbody here(SWF) who knows that name respects that name. That is not the reason I go with a DSB though. If you visit the Monterey Bay Aquarium almost all of their tanks have a DSB, same with the the Kansas City zoo. Is the DSB a new idea thought of by aquarists? NO. Before deciding on Computer engineering as a major in college, I was a plain out GE major. In my ge 01 they took us to the city of vellejo's water treatment plant. One of the stages in the water treatment area is a DSB. I would say that before mother earth invented it...in the ocean. When ever I have been diving(turtle isle jp, okinawa jp, MB ca usa, coast of mexico pacific side) every reef has sand at the bottom. I've yet to see any beach with crushed coral at the bottom. I've had one system that had a so called un-identifiable "crash" it was with CC, I have yet to ever have that with a DSB
broomer5
Active Member
I see no reason to stick a syringe down in my sandbed to test the water. I know it will be foul down there - that's the intention.
I prefer to test the circulating water where my fish and corals live.
My nitrates are ZERO and I feed the tank heavier now than ever.
Not fed often - but heavy when I do.
I don't need any convincing on the benefits of a deep living sandbed in my tanks - I'm satisfied that the steps I've taken over the last year have led to a more maintenance free and healthy reef tank.
My water chemistry is dead nuts on the money - and has been for some time now. I could not always say this in the past.
I admit that there are other factors involved here - and just having a DSB doesn't insure success - just as having another type of substrate doesn't insure success or failure as well.
In my unprofessional opinion - there's just a lot more to it than one's choice of substrates.
You're welcome to your opinion a_fender69, as we all are.
If whatever you choose as a substrate works for you ~ more power to ya !
For me and many others ~ incorporating a deep living sandbed, along with careful attention to other variables ~ works really well for us.
Just as not having a DSB works well for others.
I prefer to test the circulating water where my fish and corals live.
My nitrates are ZERO and I feed the tank heavier now than ever.
Not fed often - but heavy when I do.
I don't need any convincing on the benefits of a deep living sandbed in my tanks - I'm satisfied that the steps I've taken over the last year have led to a more maintenance free and healthy reef tank.
My water chemistry is dead nuts on the money - and has been for some time now. I could not always say this in the past.
I admit that there are other factors involved here - and just having a DSB doesn't insure success - just as having another type of substrate doesn't insure success or failure as well.
In my unprofessional opinion - there's just a lot more to it than one's choice of substrates.
You're welcome to your opinion a_fender69, as we all are.
If whatever you choose as a substrate works for you ~ more power to ya !
For me and many others ~ incorporating a deep living sandbed, along with careful attention to other variables ~ works really well for us.
Just as not having a DSB works well for others.
phil1964
Member
I thought all you guys were bonkers with this DSB thing.
2 inches is fine. All it does is displace valuable water.
I have put in 180 pounds of sand in a 180. I never did sand before but definately want more. I like the look. I am thinking another 100 pounds will do it. Not deep by some standards but you cant all be wrong! I figure if I am going to put it in now is the time. Would 280 pounds be ok? Who thinks I should go more?
2 inches is fine. All it does is displace valuable water.
I have put in 180 pounds of sand in a 180. I never did sand before but definately want more. I like the look. I am thinking another 100 pounds will do it. Not deep by some standards but you cant all be wrong! I figure if I am going to put it in now is the time. Would 280 pounds be ok? Who thinks I should go more?
broncofish
Active Member
IMO 3"-5", but I am no expert.
jlem
Active Member
I am a fan of a shallow bed with lots of live rock. DSB's may be more efficient than live rock but you have to have the bioload to really utilize both the live rock and the DSB to it's full capacity. 4-6 inches of sand plus live rock is a ton of area and a big portion of the tank filled with sand. to stock a tank enough to utilize all that I would think would overcrowd a tank and cause other problems. I don't deny the great ability of a DSB to lower nitrates, but a properly stocked tank full of live rock ( not packed to the glass full ) I would think probably would remove the need for a DSB, it has in mine. But my tank is not yours, and what orks for you may not work for me and vice versa
jlem
Active Member
It doesn't hurt to have more filtration but is 4-6 inches of space lost on sand really needed if it isn't benefiting the tank much. C/C is a biological filter. Any surface will be populated with nitrifying bacteria no matter what it is, even glass. We just clean it off when we clean the glass. Also, a regulary vaccumed C/C bed will remove most gunk before it breaks down. a C/C substrate only becomes a cess pool of waste if it is not maintained, which if you do water changes it only takes a little more work to vacumm out C/C than to just drain water. I think that DSB's are usefull but not always needed.
scarybo
Member
Not an expert, but my opinion.
DSB cant be beat for denitrification thru natural reactions. If it is functioning properly the water within it should be foul. Correct me if I am not correct..but to convert nitrates to nitrogen gas the bed would convert it back into nitrite at some point, but since the water is moving slowly thru the bed it is a controlled reaction. Sometimes DSB can malfunction, but the risks are very very small if it is set up correctly. The danger of stirring a DSB is you release the gases within it. It doesnt mean the DSB is flawed it just dangerous to interupt a chemical reaction without controls
CC will act as a biological filter, but it will not convert nitrates. The flow of oxygenated water is too fast due to grain size. In my opinion..if you are going to use CC just for biological filtration, a wet/dry would do the same job and allow greater ease of periodic cleaning.
DSB cant be beat for denitrification thru natural reactions. If it is functioning properly the water within it should be foul. Correct me if I am not correct..but to convert nitrates to nitrogen gas the bed would convert it back into nitrite at some point, but since the water is moving slowly thru the bed it is a controlled reaction. Sometimes DSB can malfunction, but the risks are very very small if it is set up correctly. The danger of stirring a DSB is you release the gases within it. It doesnt mean the DSB is flawed it just dangerous to interupt a chemical reaction without controls
CC will act as a biological filter, but it will not convert nitrates. The flow of oxygenated water is too fast due to grain size. In my opinion..if you are going to use CC just for biological filtration, a wet/dry would do the same job and allow greater ease of periodic cleaning.
bang guy
Moderator
Close, but the denitrifying bacteria actually convert Nitrate directly to Nitrogen. The danger of stirring the sandbed is an increase in Nitrate in the water column and the escape of Sulfide. There won't be a lot of Sulfide, but enough to make your nose hairs curl In addition stirring the sandbed via fish, starfish, Horseshoe Crabs, etc. disturbes the animals that move the water through the bed. It can take weeks to recover from a small amount of stirring.
In addition stirring the sandbed via fish, starfish, Horseshoe Crabs, etc. disturbes the animals that move the water through the bed. It can take weeks to recover from a small amount of stirring.
wamp
Active Member
jlem
I think you kinda missed the point on a DSB. Yes, any surface area will house bacteria, but not anarobic. A DSB houses anarobic bacteria which is soley responsible for the conversions of nitrates not ammonia or nitrites.
I agree, however, that they are not necessary. I have had many tanks with very low nitrates without a DSB. Water changes and carefull stocking should always be a priority. Some, alot, of people think a DSB will allow them to add a bigger bio-load and that's not the case. Nitrate removal is the slowest process in the nitrogen cycle thus, a larger load will need more time for conversion.
On the other hand, My next tank will have a DSB. again... I do think they provide more than just filtration benefits.
I think you kinda missed the point on a DSB. Yes, any surface area will house bacteria, but not anarobic. A DSB houses anarobic bacteria which is soley responsible for the conversions of nitrates not ammonia or nitrites.
I agree, however, that they are not necessary. I have had many tanks with very low nitrates without a DSB. Water changes and carefull stocking should always be a priority. Some, alot, of people think a DSB will allow them to add a bigger bio-load and that's not the case. Nitrate removal is the slowest process in the nitrogen cycle thus, a larger load will need more time for conversion.
On the other hand, My next tank will have a DSB. again... I do think they provide more than just filtration benefits.
scarybo
Member
I'm not sure where I read the data but, Nitrate is converted to Nitrogen gas in a series of steps.
Nitrate (NO3) -Nitrite (NO2) - Nitric Oxide (NO) - Nitrous Oxide (N20) - Nitrogen gas (N2)
This type of denitrification within a DSB combined with Macroalgae growth for nutrient export is the best way I have heard to achieve low or zero nitrates.
Nitrate (NO3) -Nitrite (NO2) - Nitric Oxide (NO) - Nitrous Oxide (N20) - Nitrogen gas (N2)
This type of denitrification within a DSB combined with Macroalgae growth for nutrient export is the best way I have heard to achieve low or zero nitrates.
bang guy
Moderator
Originally posted by SCARYBO
I'm not sure where I read the data but, Nitrate is converted to Nitrogen gas in a series of steps.
Nitrate (NO3) -Nitrite (NO2) - Nitric Oxide (NO) - Nitrous Oxide (N20) - Nitrogen gas (N2)
I can fully believe that is a potential Nitrate > N2 conversion. This is the conversion I learned:
C106H263O110N16P + 91.4 H+ + 94.4 NO3- > 106 CO2 + 55.2 N2 + 177.2 H2O + PO4---
In my model the Nitrate is directly converted producing CO2 as a by product. In your model O2 would be produced in quantities significant enough to kill the anoxic bacteria unless flushed constantly with oxygen poor water. Perhaps yours is the Plenum version where the flow rate is higher than in a DSB?? Good future topic IMO.
Guy
jlem
Active Member
wamp. How did I miss the point of a DSB. In every statement I acknoledged the great ability of a DSB to lower nitrates and I don't think I said that C/C would lower nitrates. C/C is a biological filter. C/C will take care of ammonia and nitrite, and if you never cleaned your glass and had a bare glass tank with nothing but a few fish then the glass would grow bacteria to take care of the ammonia and nitrate. Now if nitrifiyng bacteria means the reduction in nitrates then I used the wrong word and my mistake. I meant that any surface can become a filter for ammonia and nitrite reduction, but like you said a DSB will take care of the nitate, it just takes alot of room in the tank. When I read most of the DSB posts they give off the impression that nothing but a DSB will reduce nitrates and that just isn't true. I am not knocking the ability of DSB, just the percieved impression that they are the only way to go, which you wamp have never said. How many threads have you read where a new hobbiest asks what is needed for a fish only tank and people start throwing out live rock at 4.00 a pound and 4-6 inches of sand which if you live in 80 percent of the country southdown is not available, but that is a whole different subject so I'll shut up.