Deep Sand Bed

[Chris-]

Hi davelin315, well, of course, and not because you said this, I was also thinking of two ways to go about the reverse flow. One idea was not having any flow at all and the tubes capped, or, very low flow and filtered water. One side would be capped and the other low flow side would have such low flow that it could not clog the substrate, as it was technically not pushing anything "up" into the sand. Once every three months the other tube would be uncapped and the whole under side flushed out.

 

According to Jaubert in her system, "the gravel does not become extremely dirty with accumulated detritus because the denitrifying bacteria utilize the detritus". So, in essence, wouldn't the same thing happen in a fine DSB, and, weather it is in the main tank with detritus or remote with filtered water? Of course a filtered RDSB has less of a chance of getting clogged, thats obvious, but, according to Jaubert, mine should not get clogged either (under "my" circumstances).

 

I have said before, I feel that there is NO "set it and forget it" sand bed. Whatever you put in the tank, be it rocks, sand etc needs to be cleaned and maintained some how, at some certain interval(s). People are amazed at Pauls tank but it is simple, he CLEANS them! I am amazed at Paul for having a tank for so long. But really, it is simple, clean! DSB's and RDSB's are only tools to help us keep fish. I looked over all the options and decided that a plain DSB with a little work here and there is what "I" need. It is not the same for everyone else. Everyone has to look at the pro's and cons of each setup and decide what they want to deal with.

 

P.S. This was written before Paul posted....thanks Paul!

Edited April 17, 2010 by Chris-

[paul b]

According to Jaubert in her system

 

Jean Jaubert is a guy. A French guy.

 

but it is simple, he CLEANS them!

 

Oh no, the secret is out.

 

My theory, and it is only a theory, is that nothing will work forever if you can't maintain it.

But a system that can be maintained, can last forever.

I know many people don't think in forever terms but neither did I when I set up my tank. It just eventually became forever.

My system I am sure is not the best, but it can be maintained at least to stay as it is.

I do have to stir up some gravel a couple of times a year but I have only did a really good cleaning after 25 years. I did not have to empty the tank for that but I did have to move the rocks to one side while I cleaned the gravel there. It may have lasted much longer but I also wanted to see what was living under the filter plate.

I was amazed, it was all tiny red tube worms. Very healthy looking tube worms and no hydrogen sulfide and no smells.

If they come up with a way tomaintain a DSB, it should be fine but logisticly, I don't see how to do that.

In another 15 years I may clean this again, I will see if I have time.

 

Edited April 17, 2010 by paul b

[Chris-]

Jean Jaubert is a guy. A French guy.

 

My system I am sure is not the best, but it can be maintained at least to stay as it is.

 

 

A French "guy", eh? Whoops!

 

I was looking at the options and was about to go your way before I read up on your method. I decided not to go your route as all I had was theory's and no hard evidence on the outcome. What intrigued me about you, Paul, is I had found someone that would be able to tell me, and others, a story of how that setup went for them. In the meantime, out of all the ways I could go, I went with known names that stated DSB are "okay" to use. Not the end all be all, but, okay to use. I knew an oolitic would not be 100% hands off (long term that is), and I am surprised people think it is. I also wanted to have sand sifting gobies. I like their activeness plowing through he sand. I knew the pro's and con's of having them. I also tried to get an idea of what microfauna lived in the fine sand I was goig to use, and, out of all the diff grains of sand, and fauna that lived in each type of sand, again, I went with oolitic.

 

I think that out of all the ideas for a sand bed, for ease of maintenance and trouble free operation, yours would be the best. Though I would like to find a little finer dolomite than what you have used, it is all good. Other than that, your setup is perfect to me, if I was not playing with the oolitic.

Edited April 17, 2010 by Chris-

[paul b]

Chris, don't forget, I am about the only one using this system so I guess that means

15,000 people are using the wrong method.

[astroboy]

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...

 

 

When I moved I set up an RSDB (29 gallon tank, RSDB: 5 gallon bucket with 18 inches of sand/mud, alot of flow over the top), and I've had zero nitrates, despite alot of corals and overfeeding the clowns. Based on a 75 I had with a DSB and RDSB, if you're underskimmed or whatever, you'll have alot of organics building up in the DSB which will take the RDSB perhaps a year to break down to the point where nitrates are zero.

 

I recall Basser9 mentioning that he never does water changes,and has been running marine tanks for 20 years, and as I recall runs something like a 90 gallon with an RSDB with 16 inches in a 55 or 75 gallon tank. I must say, the notion of setting up a system that doesn't require water changes appeals to me. I'd sure like to hear more about Basser9's setup (hint hint)

.

 

Bottom line: I don't think I've ever heard anyone claim an RSDB did any harm (anyone??, Beuhler, Buehler?), and in my experience they seem to work quite well, especially if you start with a 'clean' sand bed in your display tank at the start.

[davelin315]

When I moved I set up an RSDB (29 gallon tank, RSDB: 5 gallon bucket with 18 inches of sand/mud, alot of flow over the top), and I've had zero nitrates, despite alot of corals and overfeeding the clowns. Based on a 75 I had with a DSB and RDSB, if you're underskimmed or whatever, you'll have alot of organics building up in the DSB which will take the RDSB perhaps a year to break down to the point where nitrates are zero.

 

I recall Basser9 mentioning that he never does water changes,and has been running marine tanks for 20 years, and as I recall runs something like a 90 gallon with an RSDB with 16 inches in a 55 or 75 gallon tank. I must say, the notion of setting up a system that doesn't require water changes appeals to me. I'd sure like to hear more about Basser9's setup (hint hint)

.

 

Bottom line: I don't think I've ever heard anyone claim an RSDB did any harm (anyone??, Beuhler, Buehler?), and in my experience they seem to work quite well, especially if you start with a 'clean' sand bed in your display tank at the start.

 

Yeah, I'm not taking any action on mine and am limiting water changes again to see if it does have any impact long term. I will, however, if I ever find the time, remove the substrate from one area as that is most likely a major culprit in my nitrates.

[Chris-]

davelin315, do you get a lot of bubbles popping up from the surface of the sand? I swear every time I look at my tank it looks like I have one of them air treasure chests, lol.

[lhcorals]

I really appreciate all the comments. I have decided to run the RDSB. I am going to go with a 75 Gal tank instead of the 10 Gal. I think that would serve more purpose on the water volume i am going to have.

[lanman]

I built a remote deep sand bed about a year ago? Okay - it was 1.5 years ago. http://www.wamas.org/forums/topic/26319-fresh-step-remote-deep-sand-bucket/page__p__231206__hl__fresh%20step%20__fromsearch__1entry231206

 

I haven't really noticed much difference, but between the RDSB and the Refugium, I now only have to change 10% once a week to keep nitrates in the 'reasonable' range. For a while it was twice a week. So maybe it's doing something.

 

bob

[astroboy]

I built a remote deep sand bed about a year ago? Okay - it was 1.5 years ago. http://www.wamas.org/forums/topic/26319-fresh-step-remote-deep-sand-bucket/page__p__231206__hl__fresh%20step%20__fromsearch__1entry231206

 

I haven't really noticed much difference, but between the RDSB and the Refugium, I now only have to change 10% once a week to keep nitrates in the 'reasonable' range. For a while it was twice a week. So maybe it's doing something.

 

bob

 

My 75 had been underskimmed for at least a year, with a sand depth of 4-7 inches. Over that time I think alot of organics accumulated in the sand bed. I could do 50% water changes, and within 12 hours the nitrates would be almost exactly where they were before. I have to think that was a result of the stuff the sand bed accumulated. When I set up the RSBD it took at least a year (with a better skimmer) to have the nitrates start to move downward. Possibly really stirring up the tank sand bed would have moved things along quicker..... But its been my experience that if you start with a clean sand bed, your RSBD will give you near-zero nitrates within a month or so.