DSBs & long term viability, the evidence against..

[lightningstrike]

IMHO, 6 months is way 2 short to judge the pros and cons of having a DSB.

maybe this 2 articles can reveal a little more insight,

Sandbeds, Reefkeeping-Oct issue

Sandbeds, Reefkeeping-Nov issue

[Ancelot]

Okie.. i think i am gg to move abit off the topic. Just thinking abt the infauna blueheaven said. are you refering to the macroalgae?

Honestly, not flaming anybody, how sure are we that it is good to put macro algae into the refugeim and not leave it empty with only DSB? Are we really following what the experts say or are we just like other lot of people following what other people say based on their experiences?

I think i was trying to say abt the toliet is that it is always better to find an easy and fast method out of a problem rather than let the problem be there and slowly get solved by something else. Very much like the theory of the toliet bowl with a flush as stated by Creetin and supported by me.

Just my 2 cents worth...

[Ancelot]

I have done an experiment on the effects of creating a totally anaerobic condition and I am surprised that a hell lot of hydrogen sulphide is produced. But what interests me most is that when air is introduced to the setup, after a few days, the black stuff cleared a little. But anyway, I'm still monitoring the setup for a few more days to see of there's any changes.

Dude, i think you just activated the plenum system. In plenum it states that if the saturation of oxygen drops below 0.5mg/L, hydrogen sulphide will be produced. So i think you just did that thats why when you add air bubbles back into the tank, the amount of hydrogen sulphide produced dropped significantly..

Just my 2 cents worth..

[Ancelot]

Actually DSB and plenum not much difference apart. Yes they are different but the differences i find it not very significant..

Just my 2 cents worth..

[blueheaven]

To reply to bro Ancelot,

Infauna is not macroalgae but actually refers to the small animals you find in the sandbed itself. It is these infauna that actually cleans the bed from detritus and also slowly shifts the sand to prevent the creation of a totally anaerobic region.

And as for my experiment, I only used some sand and some small pieces of LR in a covered tube. But its not the production of the black stuff that is decreased but the amount of black stuff decreased significantly.

[Creetin]

But its not the production of the black stuff that is decreased but the amount of black stuff decreased significantly.

hey BH, wondering wats the diff btw the production of the black stuff that is decreased but the amount of black stuff decreased significantly.

and whats the black stuff?

[Ancelot]

Ya.. sorry i mean the amount of hydrogen sulphide. =)

less sand and some LR, and lots of H2S, sounds very much like plenum to me. In this case, your LR is acting as your sandbed in plenum. But i must ask: does H2S really smells like rotten egg?? I never smell it before!"

Well, infauna is small crustaceans then better keep liverocks than macroalgae?! More places for them to hide and not to mention you can always do the recharge kit inside your sump? anyway these animals dont come together with the sand. They are actually good hitchhikers from the rocks your macroalgae are attached on or the liverocks in your sump or your main tank. Not all live in the sand, mostly i notice them hiding among the rocks. Do they really clear up detrius i dont know cause i always put in those snails (dont know if its nerite or cerite snails) that do the cleaning inch by inch or i will take my gravel washer and do the washing.

Talking abt recharge kit i think doing the americans' style is the best i can think. But space is always a constraint or else...*tsk tsk*

Just my 2 cents worth...

[Ancelot]

hey BH, wondering wats the diff btw the production of the black stuff that is decreased but the amount of black stuff decreased significantly.

and whats the black stuff?

Creetin dude, its the same thing just phrasing different.

i believe the black stuff should be H2S gas dissolved inside the saltwater..

Just my 2 cents worth

[blueheaven]

Actually infauna mostly originates from the rocks you place in your sump

Unless we can ensure rapid reproduction going on, we're gonna need recharging every few months or so

And yeah the difference between the two phrases are the way I phrase them

[Ancelot]

Actually infauna mostly originates from the rocks you place in your sump

Unless we can ensure rapid reproduction going on, we're gonna need recharging every few months or so

And yeah the difference between the two phrases are the way I phrase them

Yeah! I agree! Recharge part.. hmm.. can only be one route. Intense light plus lots of LR and no fishes inside the refugiem then your copepod population will multiply.. if no algae for the copepods to graze, their population will drop drastically. tats what i know from my observation. best if can feed them with DT then VOLIA! a culture station and a successful lots of copepods.

Anyway i think I am way out of topic.

[alanseah]

lolz.. anyway may i know all these reason if your own thinking and make it up yourself or got any lab testing and sci proven..???

Well I can only say there is many different method out that... some success with this method while other follow and never success in it.. and how u going to explain it..

and beside has anyone see a dsb problem as per describle the problem after long use???

[Achilles Tang]

I like to remind everyone to discuss the issue and not off topic stuff like discussing methods of copepod cultivation.

[blueheaven]

Actually i was thinking, what could be the potential problems with keeping a DSB for long term say like 4-5 years? I mean if you can maintain it well for a few years, why not long term?

[Terryz_]

I have done an experiment on the effects of creating a totally anaerobic condition and I am surprised that a hell lot of hydrogen sulphide is produced. But what interests me most is that when air is introduced to the setup, after a few days, the black stuff cleared a little

It is becos hydrogen sulphide is produced due to the anaerobic condition in the sandbed, if i am not wrong... So when you introduce air into the setup, it increase the O2 concentration in the tank, so the hydrogen sulphide will decrease abit...

[Ancelot]

Replying to blueheaven's note:

I think the hard part comes when it is long term. I always talk abt something if everyone notices - tats attitude. If you have the right attitude it is absolutely possible to have an effective DSB for 3 ,4 or maybe even 5 years or more. But if you are going to slack abit day by day, one may start off with a good tank, but after 5 years, all good stuffs add up equals to nothing. So answerng alanseah's qns abt why there are successes in some people in utilising a certain system whereas others didnt, attitude is what makes that difference.

AT,

I dont know if i have gone off topic but i certainly hope to see more discussions inside this topic. Hopefully, the old reefers can contribute to this topic. I find it very worth to discuss abt this topic because personally i am a fan of DSB. thanks.Apologies tat i stray off to copepod cultivation.

Just my 2 cents worth...

[Terryz_]

Anybody got experience with plenum... Going for a plenum system in my next setup...

[Marineman]

Some hobbyist has great success with DSB whilst others had their tank crashed esp when they try to stir up too much of the sandbed releasing PO4 etc to the tank.

IMO to have an effective DSB over a long period, I suppose one has to do some form of maintenance like cleaning the DSB from time to time little by little but then ther are areas of the sandbed which is difficult to access, this will lead you to rearrange your tank display from time to time. this is a time consuming task and not everyone is game to it eventhough you may be a hobbyist. On the other hand you can imagine if your powerful powerhead falls off from it's original position and caused a sand storm, the picture would not be too pleasant.

By having a bare bottom tank with a refugium as a filtration media, it is easier to clean the tank although it may not look so nice, it's a compromise fro easier maintenance.

Like I said, there are pro and cons as both system have proven to be successful but there are more cases of tanks crashed with DSB than those with barebottom. One of the disadvantages of clear bottom is that you cannot keep livestock which requires a sand bed, like tube anemones and some fishes and crustaceans.

Either way to be succssful, one has to compromise,

[Terryz_]

less sand and some LR, and lots of H2S, sounds very much like plenum to me. In this case, your LR is acting as your sandbed in plenum

Actually, I quite disagree on this statement...

Plenum will actually prevent the formation of Hydrogen Sulphide... And Plenum also require a considerable amount of Sand although less than DSB...

I think you got the whole plenum thingy wrong...

It seems i have gone off-topic too...

Pai seh... Pai seh...

[Achilles Tang]

Like I said, there are pro and cons as both system have proven to be successful but there are more cases of tanks crashed with DSB than those with barebottom.

By what statistics do you say this?

[RAV-65]

I have done an experiment on the effects of creating a totally anaerobic condition and I am surprised that a hell lot of hydrogen sulphide is produced. But what interests me most is that when air is introduced to the setup, after a few days, the black stuff cleared a little. But anyway, I'm still monitoring the setup for a few more days to see of there's any changes.

Juz my $0.02...

by introducing air, does that not defeats the purpose of the DSB whereby in an area starved of oxygen, the anaerobic bacteria strives to absorb nitrates??

[blueheaven]

Actually the trick to setting up a DSB is to create an "anoxic" region whereby its drastically deprived of oxygen but not totally anaerobic. A successful DSB doesn't need any cleaning on that part as the infauna will do the job and there would not have any hydrogen sulphide production as there are no anaerobic areas.

Although a DSB must be as big as possible, I opted for an in-sump sandbed as ot will be easier to monitor the progress. And for those who want sand in your tank, you can still have an inch or two of it

[lightningstrike]

aerobic: taking place in an oxidizing environment.

anaerobic: taking place in a reducing environment, oxygen is still present, but unable to support aerobic respiration.

anoxic: lacking oxygen. in contrast, areas in which oxygen is not present are both anaerobic and anoxic.

[Ancelot]

A note to everyone:

Hydrogen sulfide is not hydrogen sulphide. Chemical symbols are diffferent so does the ionic formula. And it is hydrogen sulfide tat will be produced when oxygen saturation drops below 0.5mg/L in plenum not hydrogen sulphide.

With regards to Terryz_:

Not a debate. Formation of hydrogen sulfide i believe is an imminent process (correct me if i am wrong). I do not believe you can run away from it Even if in DSB, you will get hydrogen sulfide and not to mention inside plenum. Hydrogen sulfide formed in plenum is because of the lack of oxygen saturation inside the system and i believe if i am supposed to starve my DSB of oxygen, it will also produce hydrogen sulfide. The reason why we didnt get it is because of the constant exchange of gases through our skimmers, the waves caused by our currents, our occasional water top ups etc. So our oxygen level in our tanks can never really drop down to <0.5mg/L without any unforeseen circumstances but given for blueheaven, i do not know how he managed to do it.. but i believe tat gas sure stinks! If you ever watched documentaries, when they filmed life deep under the ocean in those trenches, you will see gases coming out of some chimneys, those are hydrogen sulfide. and ya, its very black!

[Ancelot]

Back to the topic:

Everyone been very skeptical when i said about adding an air stone to DSB, everyone said i was wrong because denitrification only takes place where there is a lack of oxygen. Thats correct! Nothing wrong about it. But adding oxygen to the DSB, I am supporting the process of Nitrification. Pls bear in mind tat denitrification and nitrification are two different things.

Ammonia will be oxidised by the bacteria called Nitrosomonas spp. into nitrite and nitrite later oxidised into nitrate by a bacteria called NItrobacter spp. This process is an oxidation process. It therefore requires oxygen.

This is nitrification process.

And whereas for denitrification, i believe everyone knows about it.

So by adding oxygen to the DSB, it has been proven that it is possible for these two processes can be taken place in close proximity. "Anoxic microsites within fecal pellets and detrius will provide a habitat for anaerobic bacteria, while surrounded by porous aerobic waters" as quoted from Julian Sprung's book

And by adding oxygen to your tank via an air stone, you oxidise ammonia into nitrate faster by rapidly causing the aerobic bacteria to work more since they have more oxygen now. And you have higher nitrate but lesser ammonia. And given for times like now, isnt it becomes easier that we can remove nitrate faster by the effective breakdown of nitrate to nitrogen gas by the bacteria in DSB and also through our effective skimming (i assume everyone has a good skimmer)?

So i seriously dont find anything wrong to add oxygen to my DSB. Afterall, its no different from adding ozone. Ozone is just O3 which is an unstable structure compared to oxygen, but ozone when exposed to other elements in water will still break down to give oxygen. Given for this, why not save some money and use a cheaper source of oxygen?

Just my 2 cents worth..

[Alentino]

I strongly believe DSB works as it did in nauture for millions or thousands of donkey years. Eric Borneman has been using it for years with success and no problems as he said so in his recent reefkeeping articles. The only problem is only mis-managed sand beds.

Studies by marine biologists also agree with his suggestion that "sand sifters" or anything like that can decimate sand bed faunas. It is found that when sting rays digs and shuffle the sand bed to forage for food, pods and critters will be killed in its trail. So it is important to leave the sand bed as it is by not stirring them or stuffs and not adding TOO MUCH "sand sifters" in small aquariums. They will be decimated to oblivion. But i'm not sure how much is too much and i feel that adding just one or two should'nt hurt.

As it is in nature, no sand bed is complete and fully functional if there is no live in it. The bethnic pods and critters are part of the bio-diversity and no ecology system can function without bio-diversty. They also important contributors to nutrient recycling in reefs by breaking down/feeding on settled detritus and waste. In my opinion, if there is little disturbance to sand bed to kill them and a continous supply of waste food, the bethinc pods and critters should'nt go through a population crash and make sand bed devoid of life.