Setting Up A Plenum sandbed, The Correct Way

[zephyros]

Hi frens,

With reference to the article by Julian Sprung

- Jaubert's Method, the "Monaco System," Defined and Refined

URL: http://www.advancedaquarist.com/issues/sep...002/feature.htm

I want to setup a DSB (Deep Sand Bed) for several reasons,

such as keeping jawfish, sand shifting gobies, denitrification etc

However, the dread of hydrogen sulfide building up in the DSB, and one

day going "bomb" really make me think twice abt the DSB.

Is there any basis for this "fear"???

The above article advices setting up a plenum of abt 2-3cm below the

DSB. The purpose of the plenum is, I quote,

There is some explanation for this of course, so my testimonial is not simply in support of a mysterious phenomenon. The plenum provides a layer of water that maintains a level of dissolved oxygen above zero. Therefore the gravel in Jaubert's system is sandwiched between the highly oxygenated aquarium water circulating above it, and the plenum water, which maintains a low but generally stable level of dissolved oxygen. Being sandwiched between these oxygenated zones tends to prevent the formation of hydrogen sulfide, a common occurrence in deep sand beds without a plenum.

OK, I am no chemical know-all, or rather I am a chemical know-not

Hence, like to hear from reefers about DSB, is it a time bomb that we are

keeping.

Zephyros

[pospeh]

I haven't read the article you linked, but the Monoco system (AKA Jaubert, AKA Plenum) is completely different from the DSB method advocated chiefly by Dr. Ron Shimak.

DSB is simply 4-6 inches of fine grade sand.

A Plenum creates 3-4 layers of sand through the use of grating and nettings.

There has been some evidence that DSB, after operating for 2+ years tend to crash after buildup of heavy metals (as explained by Shimak) or just simple deitrus and hydrogen sulfide buildup.

Plenums systems are supposed not to be subject to this tank crash syndrome. Sprung is a very respected authority in reefing (he wrote the 5 part "bible"), so I suppose his views can be trusted.

[PornStar]

wow...long write up....but i'm not at that level to provide any comments....

anyone?

[Tanzy]

My plenum is 4+ years old and no problems with the sand bed. At least not yet. In the future I'll continue to use plenum systems as I find that #0 sand not suitable for high water energy environments.

[hijackng]

hi

can i use #03 sand?

cos i find that #01 sand can slip through the screen.

[Tanzy]

I suppose you could. Why don't you try two layers of screen/mesh to prevent #1 from getting through or #2 sand.

[zephyros]

I haven't read the article you linked, but the Monoco system (AKA Jaubert, AKA Plenum) is completely different from the DSB method advocated chiefly by Dr. Ron Shimak.

DSB is simply 4-6 inches of fine grade sand.

I think somewhere, someone mentioned that Dr Ron actually advice to

"tear down" and rebuild the DSB every 4 years.

This is definitly not something that I am planning towards to do every 4 yrs.

My plenum is 4+ years old and no problems with the sand bed. At least not yet. In the future I'll continue to use plenum systems as I find that #0 sand not suitable for high water energy environments.

Tanzy, just a confirmation. You are setting up yr DSB as describe in the

"Monaco System"

If that's the case,

1) how deep is your plenum?

2) how deep is your sand (DSB)?

3) what size of sand are you using?

4) "high water energy" - do you mean high flow rate of the water?

Thanks for your input

Again, someone in reef central forum suggest to keep in DSB in a separate

tank (ie refu tank), so as to "disconnect" it from the main tank. In this way, the

DSB can be tear down and rebuild periodically, say 3-4yrs.

But I want the jawfish in the main tank !!!

Zephyros

[hijackng]

I suppose you could. Why don't you try two layers of screen/mesh to prevent #1 from getting through or #2 sand.

Two layer of screen, will it effect the diffuson?

Erh... i think there is no #02 sand in singapore.

[Tanzy]

My plenum is 2" thick followed by 2" of sand then a mesh with another 2" of sand for a total of 6". I use #1 sand plus sand from my older tank which is about #2 or 3, not a lot but it's on the surface.

Strong currents, yes.

If you intend to keep a jawfish, I would suggest that you have your main denitrification filter outside the main tank. These guys will aquascape the tank for you. Don't be surprised if they stack one end of your tank with 8" or more of sand.

[jc85]

Can you guys describe in more details how you created your plenum? Like, using egg crate or PVC or etc, etc..

[Achilles Tang]

I just changed the title from DSB to plenum.

[zephyros]

Can you guys describe in more details how you created your plenum? Like, using egg crate or PVC or etc, etc.. 

Attached is a pic from the article

Zephyros

[zephyros]

My plenum is 4+ years old and no problems with the sand bed.

Tanzy, what is the reason that you chose to set up a plenum sandbed, as compare to a normal DSB? I mean if it is because of the high current flow, then u would

always have a DSB with bigger sand size. But why a plenum???

Zephyros

[Tanzy]

I don't trust Ron Shimek, that's all. Neither do I like Bob Goemanns. Maybe it's because of Julian Sprung. I just gave it a thought before doing anything. DSB has been around for a long time, so it wasn't a brand new idea 4 years back. There has been quite a lot of complains by then but no one really said anything about plenums, so I built one.

[Achilles Tang]

I think plenums are just DSBs that are set up the harder way!

They are supposed to function the same way with little or no difference in effectiveness.

Most people just tell you to setup a DSB right away and don't worry about setting up the plenum plate and then worry about the plenum plate collapsing later... which gives you... a shorter DSB!

[flubberina13]

I think plenums are just DSBs that are set up the harder way!

They are supposed to function the same way with little or no difference in effectiveness.

Most people just tell you to setup a DSB right away and don't worry about setting up the plenum plate and then worry about the plenum plate collapsing later... which gives you... a shorter DSB!

[NormanH]

cos i find that #01 sand can slip through the screen.

What I did was after the first layer of screen, I lay the second layer with a 1" filter floss. It worked well with no.1 sand, but now i'm beginning to worry the effectiveness of it.(imagine how much air will be trapped inside the filter floss.) Can someone pls comment?

[Tanzy]

What I did was after the first layer of screen, I lay the second layer with a 1" filter floss. It worked well with no.1 sand, but now i'm beginning to worry the effectiveness of it.(imagine how much air will be trapped inside the filter floss.) Can someone pls comment?

Any problems so far? If not, forget that it is there until something happens.

[NormanH]

The only problem is nitrate still at 50ppm after 7 mths of using plenum.

[Shark]

The only problem is nitrate still at 50ppm after 7 mths of using plenum.

probably you've used the wrong grade sand etc

[NormanH]

Using no.1 sand, 5"thick with plenum. Should be o.k.

[Tanzy]

My plenum only gave me undectable nitrates after a year. Takes time to mature. Even if it doesn't work like a plenum should, it will become a DSB.

[Clownfish]

How bout this?

Plenum_20System.pdf

[jc85]

There's a gd document on plenium setup. Thks clownfish.

[Mellow]

yup,

it takes time for a plenuum to mature before it will start bringing down the nitrates. apparently, it's abit like the nitrogen cycle where the nitrates will initially go up, then once plenuum matures, it starts to control the nitrates.I'm an advocate of plenuum too... was also told that plenuum functions better with courser sand.. my friend was liasing with this marine biologist and was told that it is better to use courser sand...somehow, it goes better for plenuums... not too sure why though.