Deep Sand Bed

[lhcorals]

I am getting ready to start on the upgrade to my system. Let me start out by giving some info on the upgrade. Right now i have a 265 Gal with a 75Gal sump/refugium. I am taking the Sump into the basement and switching to a 90 Gal. sump. I wish i could have found a 5' tank to use for the sump. What is going to be added is (1) 50 Gal (2) 40 Gal breeders used as frag tanks. Also there is a 35 Gal, and a 30 Gal breeder to be used as a refugiums. I will also be adding my wifes new 60 Gal cube into the system.

 

I have a 10 GAl. tank i am thinking of doing a DSB in. I have no experience with DSB and would like some input. I would like to know if they are worth adding and what benefits or problems can be associated with them.

 

Also is there any carpenters that would like to help frame (2) 8' walls. I have no skills at this and would appreciate any help. The pay will suck, but the food, drinks, and company will be good.

 

Thanks

Lynn

Edited April 15, 2010 by lhcorals

[Chris-]

You are going ot get a lot of conflicting answers on a DSB. While they have been documented at converting nitrates to nitrogen, how they work best, to what degree ( x amount of sand = x amount of gallons per 40ppm cleaned) is unknown and there is a lot of talk about them going sour after a while. I would say, go with a 3" min and see how it works for you. Watch your perams every two weeks, 4 months out, and go from there.

[lhcorals]

You are going ot get a lot of conflicting answers on a DSB. While they have been documented at converting nitrates to nitrogen, how they work best, to what degree ( x amount of sand = x amount of gallons per 40ppm cleaned) is unknown and there is a lot of talk about them going sour after a while. I would say, go with a 3" min and see how it works for you. Watch your perams every two weeks, 4 months out, and go from there.

 

I was thinkg of something like a 6" DSB. Is that to deep. Would it cause a problem. When you say go sour what do you mean?

[Chris-]

I was thinking of something like a 6" DSB. Is that to deep. Would it cause a problem. When you say go sour what do you mean?

 

It has never been fully explained. They just say that the sand bed absorbs toxic metals and a bunch of stuff, that, when stirred up, bring up nasties. There are/is a lot of theories what it is thats bad but nothing 100% proven, well, conclusively that is. Could be a problem if you go too deep. Then, supposedly, you get into sulpher toxic sand. Not sure how deep that point is with oolitic sugar fine sand. I have a nice 6" deep bed and have no problems "yet", 1 year later. My take on it is that as long as you move it around, stir it up a little here and there, one should be fine. Still, if I were you, I would not go deeper than 4". I went 6" because I like to play on the edge.

[trockafella]

I think he is talking about a remote DSB, not in the display.. Lynn, someone else was just asking about DSB's and coral hind posted a great link with lots of info about, just scroll back though gen discussion, its there..

[Chris-]

I think he is talking about a remote DSB, not in the display.. Lynn, someone else was just asking about DSB's and coral hind posted a great link with lots of info about, just scroll back though gen discussion, its there..

 

 

Whats the diff? Its all connected. A DSB is a DSB no matter where you use it.

[zygote2k]

Chris- do you use a DSB?

 

Lynn- I've been running a DSB on my system for over a year now. I started out with No3 at 40 ppm, and after filling the bottom of my sump with 4" of Aragamax covered with eggcrate to prevent disturbance, the NO3 dropped to nearly zero. There was always plenty of flow across the top layer of the sand and the return pump sat on top of the eggcrate. This DSB was never exposed to the light either. I was satisfied with the results that it produced and now I've had Jeff make me a custom sump that will incorporate a DSB and fuge combination.

In your case, if you can put the 10g RDSB on line after the first sump, then you won't have as much particulate matter accumulating on top. I'd try to put at least 6" of Aragamax topped by eggcrate. Put some rubble on top to make a pod bank, and plumb it in.

[Chris-]

Chris- do you use a DSB?

 

Yes. I am the one with the Starry blenny and the "Samson & Goliath" rock structure, lol. A good 6"-er in some parts.

[zygote2k]

I know who you are. I've been to your house. The sandbed in your DT doesn't really count as a remote DSB because it is constantly stirred by critters and fish. The idea is to have a completely undisturbed sand bed to work as a natural denitrification filter.

[Chris-]

true it is not a "remote" dsb, but, I only have a Diamond Goby that sucks on the top 1/4" of the surface. Nothing else really disturbs the sand bed as I have nothing in there.

 

Also, one of the things they say you want IS something stirring it up. Not all at once and not a lot of critters either. The idea is that if it is not stirred up, theoretically, it can become anorexic, aka toxic. Again, no one has a definite time frame or a definite sand depth for said "x" sand grain. Just because they are working for you and me could mean that we have not hit that toxic anorexic stage yet.

[zygote2k]

Chris- read up on the Jaubert method and the plenum system.

A RDSB doesn't get stirred- that's the idea. The sand bed won't go 'toxic' either.

 

Anorexic or anorexia is an eating disorder. Anoxic is the term you are looking for or maybe it could be anaerobic.

Edited April 16, 2010 by zygote2k

[Chris-]

I know anaerobic, so I knew it was the other. I think anoxic may be correct. I tried to quickly look it up on the net. I copied that word right from a line that had "deep sand bed" with it so I never thought of checking the spelling.

 

Not sure if I ran across Jaubert method and the plenum system, but I will double back on it. Just remember, there is more than one method, and, again, I spent a long long time studying DSB's, probably too long. Cant remember all I learned, but, I do remember what was most important. Out of all the ideas abound, a plenum system was not one of them, except for Pauls idea(?), which was the same as mine, just not incorporated into my tank. I wanted to go the DSB route.

Edited April 16, 2010 by Chris-

[zygote2k]

Lynn- look up the Jaubert system and the use of a plenum for denitrification. Marine Scene had a system like this for 5+ years running successfully.

[Coral Hind]

http://forum.marinedepot.com/Topic59558-13-1.aspx

[zygote2k]

here's the original-Jaubert

[Chris-]

Okay, it was the persons system I thought it was. Yes, I read up on that. To begin with, in his words

 

"Of course in any sand bed, worms, prototzoans, copepods, amphipods, and other creatures also help to maintain a healthy environment by feeding on detritus while gradually turning over the sand and gravel. "

 

So, I am not sure where you saw that the sand bed is to not be disturbed. Probably there somewhere, I just skimmed through it.

 

Second thing is I also personally do not like the fact that they talk about toxins (which I really do not believe) getting trapped in the sand. This is why, before I knew of Paul, I was the only other that thought "hey, why not reverse the water flow?". There are reasons to and not to go with this method also.

 

As said in the formentioned web page

 

"Author Ron Shimek is a proponent of the use of thick beds (25 cm or more) of fine sand without a plenum. He claims that such thick beds do not have a problem with hydrogen sulfide, and they function well for denitrification."

 

Of all I have read, if you only have a 4" sand bed, and critters (just a few) stirring it, it is as good as your going to get. Plenium 1 / DSB 1

 

Just depends on what you want to go with. I went with a basic DSB and no plenium. Maybe the OP wants to get a little creative and go plenium, nothing wrong with that.

[Coral Hind]

This is why, before I knew of Paul, I was the only other that thought "hey, why not reverse the water flow?". There are reasons to and not to go with this method also.

 

 

You were not the only one as reverse flow kits were sold by Penguin back in the 80's. In fact they are still available.

 

When they say not to be disturbed the sand bed they are talking about major disturbances and not from worms or pods. They mean larger inhabitants like engineer gobies, sand sifting fish, or something like a clown that will dig the sand out away from the host anemone.

[Chris-]

Yea, but nobody likes those kits. I have never even seen one mentioned. Very few know about them and even fewer, if any, employ them. Honestly, after all the reading I did, before I read about Paul, I never knew they sold Reverse Plenum kits. I saw plenty of regular ones though.

 

Well, zygote was trying to say mt DSB was diff than an undisturbed remote DSB. While I would have agreed with him to a certin extent, I made sure that whatever I put in my tank left my DSB alone. Even my diamond goby can not dig anywhere. All my rock work is on pedestals with stilts, and, he has his own concrete tubular house he sleeps in at night. All he does there is cover and uncover the hole. He may get carried away once a month and think he can dig to china somewhere, but, that is rare and still works for me as he is turning up the sand bed here and there, slooooowly, over time.

 

Yea, my really cool blue damsel got kicked to the curb for digging up sand a while back.

Edited April 16, 2010 by Chris-

[lhcorals]

I want to say thanks for the responses form everyone . I am just reading along and not saying anything due to the fact i know nothing on the subject . I talked to Sean at F&F about it a while back and he was telling me about a type of DSB that sound a lot like the one Rob is talking about. Sean said it works really well.

 

On that note i am still waiting to read more.

Edited April 16, 2010 by lhcorals

[basser9]

JUST PUT at lease an inch of sugar sand in every tank and you will never have nitrates....

[4inches or more if you have alot of fish]

so simple yet still most people battle nitrate problems....

 

You can stir your beds till your arm falls off and they still remove your nitrates

 

this is another myth that runs rampet in this hobby...

 

upside down sand beds work faster at removing nitrates and are my favorite..

 

Simple just add 1 to 6 inches of sugar sand deeper if you dont have a large tank

and stir if you like the white look and you will be happy...

[davelin315]

Hey Chris, Aquaclear powerheads also have a reverse flow option built into them. I used the reverse flow undergravel before and felt it was counterproductive as detritus got trapped below the plate and pushed up through the substrate (almost 20 years ago now).

 

Basser9, not sure where the basis for a 1" sandbed removing nitrates is from... you cannot house anaerobic bacteria, which is what denitrifies, in that shallow a bed without creating the anaerobic environment with artificial means. I have a 2-3" bed in my display and there is probably a single corner where the sand has built up to around 5" that it might have a slight amount of anaerobic bacteria in it. The rest of the tank, though, definitely has no areas of the sand bed that has denitrifying bacteria present.

 

As far as the sand bed is concerned, there's a difference between the two options you have had presented here. The DSB is an in tank system that relies on sand sifters to help keep it free of detritus. The RDSB is obviously a separate area that relies on the lack of detritus in the first place to keep it healthy. Both of these have the intention of providing a place for denitrifying bacteria to be housed in an anaerobic place. In a display, the top 2-3" of the sand bed will be moved around by the inhabitants of the tank and the detritus will settle into the bed. If you don't maintain the sand bed, you run the risk of it eventually building up so much detritus that your system eventually overloads and crashes due to this, especially if it's stirred up and it's all released into the system. The reason to add egg crate to it is to make sure that the bottom layer remains undisturbed. The top layer, since it's constantly being moved back and forth, and due to the depth, will always get some oxygen, hence it won't house the anaerobic bacteria. That's why you should have at least 5-6" in my opinion as in a tank with enough flow, the top few inches will most likely shift anyway.

 

On the other hand, a RDSB is meant to be a static environment where detritus does not settle. It's recommended that you have high flow over the top of the RDSB so that detritus doesn't have the opportunity to settle into the bed. The presence of the sand sifters will simply add detritus through their own life processes so that's why they recommend not having them in a RDSB. Once established, the top layer is obviously still going to be aerobic but all of the sand below that should theoretically be anaerobic for denitrification. It's not supposed to crash because you are not supposed to have detritus building up in the bed at all based on the method of feeding it.

 

I have been running a very large RDSB for quite a while now and have yet to see any results from it. I am not convinced that it doesn't work, but I'm not convinced that it does, either. My nitrates are sky high and I have a very high bio-load. The RDSB should theoretically counteract both of these, but it has yet to do so. They typically say 30 days is how long it takes it to mature, but I'm going on 3 or 4 months now with no changes. I'm still hoping it works, but so far it's a definite no go. If you check my build thread, the last posts chronicle its use. Currently my nitrates are still 50-100ppm...

[Glenn]

@Davelin315 - Awesome write-up ... +1 all the way

 

So my question to the masses - where does the egg-crate go?

- Only in the DT as a buffer from the bottom of the tank? I use egg-crate on the bottom of all my tanks so the rock is not sittin on glass/acrylic, and the fish can't dig under and disrupte the landscape. I don't see how it has any nitrate reducing role in a shallow sand bed in the DT.

- In a RDSB ??? why?

[OldReefer]

Davelin315

 

Great answer. I am a big fan of RDSBs I also did Calfo's DSB in a bucket and had some luck with it. I am surprised you are not seeing much of a reduction. Have you thought about running some the new bateria products to get it going? I am kinda amazed at how well they work.

[monkeydad]

zygote,

 

thanks for the original.

 

its interesting to read he used gravel, but more recent advise is to use fine-grained aragonite

[paul b]

JUST PUT at lease an inch of sugar sand in every tank and you will never have nitrates....

 

Where did that idea come from?

 

It has never been fully explained. They just say that the sand bed absorbs toxic metals and a bunch of stuff, that, when stirred up, bring up nasties. There are/is a lot of theories what it is thats bad but nothing 100% proven,

 

Nothing was proven and there are many theories but have you ever heard of an old DSB that is still removing nitrates? I don't mean 5 or 10 years, I mean old.

 

A RDSB doesn't get stirred- that's the idea

What exactly is that? No really, I don't know.

 

"Of course in any sand bed, worms, prototzoans, copepods, amphipods, and other creatures also help to maintain a healthy environment by feeding on detritus while gradually turning over the sand and gravel. "

 

This works great in theory but that theory is flawed. The idea of a DSB is to have an area low in oxygen, low enough so aerobic bacteria do not live. Worms, protozoa, copepods, amphipods and other creatures will also not live in that area.

 

Also the upper areas of a DSB are exposed to oxygen so the nitrogen gas that is manufactured in the lower layers could be converted back into nitrates on it's way back to the water column.

My problem with DSBs is that I have not seen where they reduce nitrates. Most people still have to change water to lower nitrates and a DSB is supposed to perform that function. I am sure they do it well for a while but those creatures will not re-produce forever, they can not go into the lower areas, there will hardly be any water circulation to those layers because there is no mechanism for the water to get there, or get back out,

and you can't maintain the thing. Sand in any size will eventually clog with dead bacteria. Dead bacteria do not disappear into a black hole. Nor do the skepetons of pods and other creatures living in a static, un disturbed sand bed. We can't see them, but they are there. Like Paris Hilton, I can't see her, but I know she is somewhere.

 

"Author Ron Shimek is a proponent of the use of thick beds (25 cm or more) of fine sand without a plenum. He claims that such thick beds do not have a problem with hydrogen sulfide, and they function well for denitrification."

 

As far as Iknow, Ron does not have an old tank to study.

 

Marine Scene had a system like this for 5+ years running successfully.

 

 

 

That of course is a good sign but even my snails are older than that. It's just not a long enough time to study, but it does prove that that type of system can last 5 years.

 

this is another myth that runs rampet in this hobby...

 

Unfortunately, almost everything in this hobby is based on myth.

 

Obviousely, I also don't have the answer. I am just trying to point out the things I have a problem with with one type of method. There are problems with all methods and in the end I feel we will eventually resort to a combination of most of them.

If I could design a system from scratch and had the resources I would design a system of plastic plates, smooth on one side and very porous on the other side. Three or four plates would be placed under a small amount of sand with about 1/4" between the plates. The plates would cover the tank bottom with the porous side facing down. There would be a slight circulation of filtered water circulation between the plates.

I feel that type of system would offer bacteria a place to live while the sand layer above could be cleaned.

It would even work better remote.

Of course I will be dead when that happens so name it after me. I think nanotubes will fit somewhere in that scenario.

 

Have a great day.

Paul