DSB and your marine tank!

[Wei]

Hi rrrobt,

why are u still saying I not using skimmer for this tank? I have already stated that i am using one. The pic u saw is a few mths old liao. The pic is taken when the tank is 1-2mth old. Well, I'm in army, back once a wk, skimmer is like a safety net to me.

Well, u seems not to get the pt. Skimmless tank is not a sure doom. Skimmer is not a 100% must have. X-japan tank has been running for 2 1/2 yr wilth an orcra that doesn't pull out any gunk. Seen AT tank, well, his sandbed is not matured yet, I estimate its only 25% working only. Dun see much life within. His rockwork also cover most of the sandbed, therefore, the sandbed cannot fully utilised. But since he got the skimmer, he can buy more time for the sandbed to mature before any algae outbreak. If the sandbed is fully functional, I think we could have lost our first customer, AT. hahaha

Running the beckett on this small tank? No no, not intend to overskim. This is for my next tank after i save up enough after i go to work. But since u mention, why not hook up as an emergency, anything went wrong, just start the skimmer. haha Alvyfoamer still affordable for an NSF.

My tank is very different now. STill adding on stuff(equipments & LR) to my system. Redoing my pipe work also. I do not have any digi cam, so anyone can buy me one. haha

U sound interested. You want an alvyfoamer too, can pm me/alvy. WIll come out kalkreactor & sulphur denitrator design in the future.

anyway, always want to ask u. Where u d/l the smilies with machine gun, cute. I might need to use it one day too. haha

Wei

[Phang]

Hey Wei,

Hmmm..... looks like you got some pretty good ideas going on there.... heh heh.... kalkreactor sounds good to me...

and yes, AT's rocks are resting on DIYed racks so wouldn't restrict the sand bed....

And most DSB only comes in fully functional after 9 mths onwards ....

Only one point to clarify... felt that a skimmer and DSB has different functions in the reef... one doesn't replace the other... a skimmer deals mostly with protein and nutrients, removing them before they even have a opportunity to breakdown into their elements in the reef... that's all the gunk in the skimmer collection cup, and of course plus many other stuff...... the DSB deals more with issues like nitrates......

Understand where you are coming from regards to a fully functional DSB, agree with you that they do provide tremendous benefits......

But given a choice, would prevent that all those nutrients be eradicated by the skimmer before they breakdown...

BTW, Wei... there seems to be an obvious bending of lights.... you are using 2 MHs????

Nice reef....

[Wei]

Hi Phang,

yup, dsb deal more on NO3 but theres a lot more. Biological & chemical wise. As i said, it depends on what u want to do with yr system. There are just many factors to consider before one go with or w/o a skimmer. End of the day, as long as u know what u doing is gd enough & yr corals & fishes thrive.

A dsb will not be up as predicted of 9 mths if u have things eating the organism in it, always disturb the sandbed, stock too fast. Pple had always believed that having super thick sandbed is gd. Apparently, its not & end up having an inefficient NO3 reduction sandbed. Sandbed over 4" will hamper the diffusion of oxygen.

nope, 1 mh only. the pic is 1 mh & 1 actinic. but remove the actinic after i got the 12K venture bulb. heehee.

Thks for the comment, but still a lot need to be done. Lots of tweaking. i go slow cos no time, no money. when the thing is fully up then borrow a cam and post a pic. but, that will be some time man, no time, no money. Now in the algae cycle stage. but still manageable, 1 wk 1 maintainence. beside, did my first water change since i start this tank. heehee. A Slacker when comes to cleaning!

Wei

[Chris]

I've had a DSB for over 1 year, about 4". Any visible signs to show that it is functional? There's dark brown things I can see 1" below the sand bed till bottom of tank. Also I seen some worms, one as long as 5" in the DSB and also some white pods and critters.

[Wei]

Hi chris,

sounds gd. yr sandbed is functioning. The worms will eat up the detrius, move the sand to prevent it to clump & move the N2 bubble up the DSB.

Wei

[Phang]

yup, dsb deal more on NO3 but theres a lot more. Biological & chemical wise.

Pple had always believed that having super thick sandbed is gd. Apparently, its not & end up having an inefficient NO3 reduction sandbed. Sandbed over 4" will hamper the diffusion of oxygen.

Wei,

It would eb good if you can share more of your knowledge regards to the above. would always be great to know more....

and also on the thickness of Sandbed assisting in efficiency in Nitrate elimination....

[Wei]

Wah...very long to reply.

I very lazy one. 1 time want me to post so long, very hard.

Go search at aquarealm. Last time I got post some long one over there. but so long liao(at least 2 yrs), dunno still got a not.

Wei

[Phang]

Wah...very long to reply.

I very lazy one. 1 time want me to post so long, very hard.

Go search at aquarealm. Last time I got post some long one over there. but so long liao(at least 2 yrs), dunno still got a not.

Wei

Great !!!!

Now all you have to do is to attach the page to connect us to good information....

See it as a contribution to strenghten our local reefers knowledge......

[Wei]

aiyo, very difficult leh. I only back once a wk.

I turn the arrow to u lah. My camp best, no internet! sian. Today got off then can post. But going out liao! heehee!

Wei

[Achilles Tang]

Wei,

I find it strange that you advocate DSBs but give conflicting advise abt the depth and the function of how DSBs work.

yup, dsb deal more on NO3 but theres a lot more. Biological & chemical wise.

Pls clarify. Especially chemical-wise.

As i said, it depends on what u want to do with yr system. There are just many factors to consider before one go with or w/o a skimmer. End of the day, as long as u know what u doing is gd enough & yr corals & fishes thrive.

Yeah.. that's common sense. It's also common sense that a skimmer is a good nutrient exporter and newbies should not go without one as even the 'oldies' here know the importance of having one.

A dsb will not be up as predicted of 9 mths if u have things eating the organism in it, always disturb the sandbed, stock too fast.

True for the livestock that eats organisms in DSB like wrasses and sand burrowing wrasses who may create more oxygen diffusion in the sand. As for stocking too fast, it will not have an impact on the bacteria in the sand unless you cause a total crash by inducing too much ammonia... but that would only mean another round of cycling.

IMO, bacteria deep in the sandbed doesn't care two hoots on what's happening above the upper levels and in the water column. All they care about is: give me conditions suited for me to survive, don't disturb me and please feed me.

Pple had always believed that having super thick sandbed is gd. Apparently, its not & end up having an inefficient NO3 reduction sandbed. Sandbed over 4" will hamper the diffusion of oxygen.

So your view is totally opposite to this theory.

According to Dr Ron Shimek, THE DSB EXPERT, the recommended depth of a DSB should be at least 6", anything more than that is exponentially dropping efficiency results. Anything less than that and you will poor nitrifying results.

The objective of a DSB is to create an oxygen-starved layer at the bottom so that anaerobic bacteria can grow and do their work ie. process nitrates to harmless nitrogen gas.

If you have a shallow sandbed, you allow better oxygen diffusion and thereby create conditions better suited to aerobic bacteria. This would, in theory, be no better than using a canister filter (which has excellent oxygen diffusion) that has little nitrifying bacteria to process nitrates.

[Wei]

Hi AT,

My meaning of chemical wise is, ex. if u place a piece of rock on the sandbed, it will cos the part of the sanded unable to break dwn no3 all the way to N2 but back to ammonium. Pt taken from Bob Goemans

U might have forget abt sand clumping up. As we all know the bacteria produce some kind of mucus when they breakdwn the NO3,etc we therefore need the organism to move the sand for us below. The main reason why a DSB or Plenum system crash/fail after a few yrs is becos of sand clump together.

I only know ROn is a Invert expert but he do have gd articles on DSB like Care & feeding of DSB. My pt of going 4" is from Bob. Well, if one has the depth in tank to have such thick sandbed, go ahead. It is very common for different author to have diff opinion. End of the day is for the reader to decide. I go for Bob pt of going 4" cos he had been researching & studying the effectiveness of a DSB and factors affecting the success & failure of one all this while. As for how to maintain a healthy sandbed, I will go for Ron cos he understand & specialise in small organism living in the reef.

I strongly believe that DSB is an ecosystem that comprise more than just completing the nitrogen cycle.

Wei

[Achilles Tang]

Hi guys,

We had an interesting debate going on abt skimmers hereand it side-tracked to DSBs. So I created this new topic and would like to have us discuss and share our knowledge. theories and practical experiences on sandbeds.

I have cut and paste the DSB posts out into this thread so lets not get confused!

------------- ok, this may look strange.... but this post is supposed to be the first post -----

[anakjoh]

Gee, AT, I didn't know DSB should not be more than 6" - I was planning on one 8" (H) x 6"(W) x 16"(L) in my upcoming refugium.

And now, Wei's saying 4" is sufficient. What's the general concensus?

[Phang]

Anakjoh,

For the moment, stick to the norm...

Wei claims on 4 inches DSB being enough have to be verified first before you jump into it....

cos how deep a sand bed also has alot to do with the grade size of sand utilised...

Stick to the following would be good...

.. get rock racks so that your LR dun rest directly on the sand so no clumping will take place....

[onghm]

Hi Phang,

Don't mind ask u some questions about rock rack on DSB.

Hope not out of topic as stacker is still on DSB

1) Do u rest your eggcrate on pvcs ?

2) Do u rest your pvcs directly on the glass or on the DSB ?

3) Is the PVC open-ended at both ends ?

4) if ans to (3) is yes, would harmful gas from bottom of DSB one day leak out thru' the pvc to the surface of the DSB ?

Thanks a million

[Achilles Tang]

Gee, AT, I didn't know DSB should not be more than 6" - I was planning on one 8" (H) x 6"(W) x 16"(L) in my upcoming refugium.

And now, Wei's saying 4" is sufficient. What's the general concensus?

No no no.... I didn't say a DSB should not be more than 6"!

What I said was that the extra inches beyond 6 or 7" will have diminishing returns.

[Phang]

1) Do u rest your eggcrate on pvcs ?

2) Do u rest your pvcs directly on the glass or on the DSB ?

3) Is the PVC open-ended at both ends ?

4) if ans to (3) is yes, would harmful gas from bottom of DSB one day leak out thru' the pvc to the surface of the DSB ?

Thanks a million

answers are...

1) no

I do not employ the usage of PVCs as light diffusers are enough if you cable tie them at right places and enforce them.....

and erh, all rock racks should rest directly on the glass bottom.... but make sure that they are evenly supported cos LRs can be heavy.......

[onghm]

Thanks Phang.

[Wei]

Hi,

smaller grain size sand allows one to achieve the low oxygen zone for the breakdown of NO3. If one is using 0 grade sand, 2.5-3" of sand will be enough to achieve that. I myself is using 3" of grade 0 & 1" of grade 1 sand. Using 4" of grade 1 will also work. If not, setup a plenum. 4" of no. 3(including undergravel) and 1 " of grade 1. This is my configuration for my previous 2.5 ft tank for 4 yrs before tearing it dwn. One can opt for all no. 1 also.

I would not opt for sandbed more than 4" is because

1) Inefficient breakdwn of NO3 due to hamper of diffusion within the sandbed. (claim by Bob Goemans)

2) If one does not seed their sandbed to have enough live organisms to move the sand, it will cause the sand to clump.

" Sediment cemention is caused by bacteria that live on the sediment surface multiplying unchecked. As these bacteria grow, they deposit a materia over and ard themselves. This material is abt the consistency of rock candy, and when the bacterial population is great enough they can thoroughly glue masses of sediments together.

In turn, this may isolate underlying sediments, causing the developmet of areas that are deprived of oxygen (anaerobic areas), and hydrogen sulfide pockets. Such areas eventually leak to the rest of the tank with disastrous results........"

Taken from "Beginners guide to Reef Aquarium Ecosystem, Keeping your live sand bed healthy is not something u want to leave to chance." by Ron Shimek, Aquarium Fish Mag, Feb 2000, Vol 12, No. 2.

3) Thicker the sandbed, the longer one needs to seed the sandbed to become "LIVE" & prevent the clumping. I have seen most pple DSB is only less than 25% live. One can hardly trace a worm burrow tunnel through the sand at the side of glass except the refugium. Therefore, personally, i think having a very thick sandbed is just like setting up a big time bomb if one isn't able to have the amount of live in the DSB or maintain the ecosystem within.

DSB can help one achieve low to hardly any traceable NO3, but one must be careful of how they setup a DSB & selection of livestock(ex. sand star, wrasses that burrow into sand), that dig into sand & eat the fauna & gd organisms.

"Only when the sandbed has had time to reach its final stable composition will it become fully functional. This will actually take several years. ......."

Taken from "Beginners guide to Reef Aquarium Ecosystem, Keeping your live sand bed healthy is not something u want to leave to chance." by Ron Shimek, Aquarium Fish Mag, Feb 2000, Vol 12, No. 2.

Therefore, depending on how the aquarist defination of a mature sandbed. Bacteria? A few months. Really Live sandbed, at least 1-2 yrs.

I, personally go for the second, which is why i let my sandbed cycle & seed for at least 2.5mths, spd up the sandbed from maturing.(MMud need to cycle & seed for at least 5 mths before adding livestock).

Aquarist abroad are able to run a fully functional sandbed faster becos they are able to get live sand, buy the organism to seed their sandbed at the inital stage of their system.

Will be back in 5 days time!

Happy Reefing!

Wei

[Wei]

Haha, get to stay out today! Heres another helpful link!

Another article by Ronald L. Shimek, Ph. D. Dearest Mudder.... The Importance of Deep Sand.

He is using a 4" sandbed with loads of LIVE.

It is another article by him that highlight the importance of establishment of a healthy and diverse sediment dwelling organisms.

I personally would suggest one to setup their dsb in their sump aka refugium as there will be min disturbance from any fish or tank inhabitants. Organism will populate alot faster as there is no predator. This way, one will be able to avoid the clumping of sandbed & depositing of hydrogen sulfide in main tank.

Enjoy & identify the critters u see in yr sandbed!

Happy burrowing!

Wei

[onghm]

After reading thru the 3 posts by Dr Ron provided by CKS in http://www.sgreefclub.com/forums/index.php...=9&t=1453&st=30

I have some queries.

Regarding DSB in sump, below is a cut-out from Dr Ron...

Quote...

DSB's in sumps are a problem. Conceptually they should work. Practically, it is hard to get them to work. The main problem is getting the detritus and excess food down to the sump. If you have any sort of sediment layer in the main tank, the food/detritus/etc. tends to remain in the main tank, where it may or may not get processed. However, it will not go to fuel the sand bed in the sump; which, in turn, will not function properly. In time - a very short time - your system will start to experience nutrient overload.

If you have a bed in the sump, you need to ensure that all the food and detritus from the main tank makes it there. You also have to ensure that the sump DSB is sufficiently large to manage the nutrient from the main tank. Unless it has about the footprint of the main tank, this is unlikely.

Sump DSB's work well as "subsidiary" units or as refugia, but not as the primary means of biological filtration.

UnQuote...

My 2ft main tank has no DSB.

I was planning to have a DSB in a 2 ft sump tank.

Based on the above, is that a no go ?

Anyone care to comment ?

Also based on the other 2 posts from Dr Ron, 2ft tank is also too small for DSB.

Min size for DSB is 40G

Many thanks.

[Wei]

Hi,

u can opt for 1" of sand and add sea cumcumber & fishes like gobies & wrasses if u are afraid that nothing is going to eat the excess food/detritus/etc in yr main tank.

One should have a big refugium as suggested. Example, 5ft x 2 x 2 should go with a min of 3 x 2 x H. Combine with macro algae, it should function well enough for the system.

Another reason I prefer a DSB in sump becos I find that after sometime, I see lesser live in the DSB, except the refugium.

Wei

[onghm]

Thanks Wei.

So that's 1" of #1 sand in main tank and refugium in sump.

Based on the below from Dr Ron again, seems like I only need 1" in sump as well ?

Don't need 4" to 6" ??

http://reefcentral.com/forums/showthread.p...t=DSB+footprint

Quote...

Such small DSBs probably contribute minorly to the biological filtration, but such a contribution is likely negliable.

Small DSBs in refugia provide a lot of habitat for small animals, and in that regard they contribute significantly to the success of the refugium in producing animals to feed the reef. However, a one inch layer of sand would work as well as a DSB for that function

UnQuote...

[Tanzy]

Please note that the sand used for DSB in the US is finer than #0 crushed coral. It's sugar fine and looks like mud, so it can't be compared to local #1 CC. They are referring to that super fine sand, so please read in context.

#1 and 2 are used for plenum systems.

[DragonGoby]

Tanzy, you talking about their "oolitic" (Actually supposed to be used to refer to the shape of the sand instead! lol) sand? Yes, it's waaay more fine than what we have here! And they've got fantastic companies who sell aragonite oolitics sand as well. Dang, if only we could get our hands on those!

Wei, just a note regarding the post where you said, "I personally would suggest one to setup their dsb in their sump aka refugium as there will be min disturbance from any fish or tank inhabitants. Organism will populate alot faster as there is no predator. This way, one will be able to avoid the clumping of sandbed & depositing of hydrogen sulfide in main tank. "

A minor point here, disturbance of the sandbed will not cause formation of H2S - au contraire, any disturbances will cause oxygenation of the sandbed layers. H2S is primarily formed in anaerobic conditions. Clumping of sandbed also has little to do with the DSB being in the main tank or not - as it were, people do report of sandbed clumping due to kalk addition or the lack of detrivores constantly stirring up the top layer of sand.

I suppose you were referring to the worm population in the DSB doing all these functions, and that fish eating the worms will hinder their effectiveness?