DSBs Frustration

[Minh Nguyen]

In keeping aquarium, the primary waste is nitrogenous waste from protein metabolism, ammonia, which is converted to nitrates. Usually one cannot get rid of nitrates from aquarium except with water change and DSB (and other natural nitrate reduction methods). LR, and process nitrogenous waste to certain extend but not to the degree of DSB. Protein skimmer can remove some nitrogenous waste before they are converted into ammonia thus nitrates.
Within reason, in a tank with DSB, nitrogenous waste is history. IMO, for the same maintenance schedule, the tank with DSB is likely to have higher water quality then a bare bottom tank. We don't even have to do any water change to keep nitrate at or near 0. This is the reason many people use DSB.
Another reason why DSB is popular is the fact that the sand can be alive with numerous animals and worms. These animals provide constant live food supply to the corals and fishes in the aquarium. This is the reason why many people including myself use DSB. IMO, we can keep many sensitive animals in tanks with DSB while it is near impossible to keep these same animals in bare bottom tanks.
The draw back to DSB is that it does not process other minor wastes, namely the next in line waste is phosphorous waste. Because nitrate in tank with DSB is virtually 0, many aquarists do not pay attention to phosphorous waste until it show up as algae in the tank. That is why many people say that their DSB crashed. I think that if one continues to pay attention to nutrient export, the DSB can last for a very long time. It is unlikely to cause problem. In my case, I feed heavily and have no problem with algae problem. I do change about 20-25 % of the water every three months, and do use a very bright light refugium for algae, Xenia to export nutrients.
I do believe that if my LSB last 10 years, then it worth the effort because I can keep much more sensitive corals due to the high water quality that come with DSB and the live food it provide.
This is about as clear as I can explain the reason why many people use DSB. I hope that it is clear and answer many questions that many reefers may have.
Minh

 

[mojoreef]

Minh that was a great post on the pros of a DSB. and it was well posted. I dont really feel that folks that had thier DSB's crash really had thier beds crashed, thier beds basically did what they were designed to do and that is to create a recycling system. phosphate to algae, algae to bacteria and bacteria to algae. In regards to DSB versus LR as a nitrate exporter, the fact that rock sheds detritus instead of sinking it I a huge plus on the LR side. It eliminates the need for replacement. The phosphate cycle that occurs in a DSB happen in the DSB and those phosphates are not available to most algae refugums. they saty with in the confines of the sand and its surface.
I think you dont put enough concern in the ammount of phosphate that we put in our tanks, Everything we add to our tank contains it. Also if you look at the studies done on additives/foods/salt mixes, then add up the ammount of these things we put in our tanks you can see how it adds up quickly. As per life forms in he sand, again everything that grows in the sand also grows in LR or in the eco systems in creates). As per water quality I would put mine up against anyones for purity and I also keep many difficult creatures.
In Dr. Rons latest admittance he says that a 6 inch DSB in a 100 gallon tank would provide filtration for 4-5 small fish and 5 corals, any comments on that, he also admits that beyond nitrogenious waste the DSB is simply a recycling center and exports nothing more, but actually sinks it.???

Mike

 

[Scooterman]

I think after farther research, Dr. Ron has discovered in aquarium use and not in a lab, the functionally of a DSB was not quite as practical.
Having about one inch very course sb; I have to disagree about the bare Bottom statements above, I test my water regular actually more other than most, and with good test kits, LaMotte and Saliflert. I think my water quality is as good if not better than the time when I had a DSB. I do change water more frequently though but did every month with a DSB also, never three months but with that said I do know people who hardly ever change their water, some twice a year in their larger tanks(500G or so). I also think I can thrive anything in my BB or 1" sb as a DSB can.
Some of your statements seem to be leaving out information or small details. It is hard to say or judge anyone without knowing Exactly what they are doing on a daily basis.

 

[mojoreef]

Not to take away from Minh. DSB's do have a purpose for some.
Scooterman that is the main problem the the details are thier. A dsb is one large biochemical cycle, which is OK I guess, but when you keep adding stuff to the cycle (and thier is no way around that) its like a snowball rolling down a hill.

Mike

 

[Minh Nguyen]

......Having about one inch very course sb; I have to disagree about the bare Bottom statements above, .....

I would say that you do not have a DSB. IMO, having a thin coarse substrate is the worst of both worlds. Not enough to perform the function of a DSB and just collect detritus. Your conclusion is invalid because you do not have a DSB.

Some of your statements seem to be leaving out information or small details. It is hard to say or judge anyone without knowing Exactly what they are doing on a daily basis.

I am not judging anybody. I have keep marine aquarium and reef aquarium using under gravel, reverse flow under gravel, fluidized, Berlin method/refugium, and DSB/refugium/skimmer.
The above are my experience. I know that my nitrate was never 0 until I have DSB. There are various corals that seem to require feeding. Success with these corals seem to come with DSB (Goniopora and Alveopora, and a few other corals.,.) One may say that Goniopora requires "dirty water" which we know that is not true. IMO, they need the feeding that can only come with a thriving DSB.



Mike,
I actually don't read what Dr. Ron wrote much anymore. I have not been on his forum regularly for a long time.
When talking about water quality, we need to consider the maintenance schedule. I never say that DSB will have better water quality then BB. All I say is that given everything the same, load, feeding and maintenance schedule, DSB have an advantage because the enormous ability of DSB to process nitrates. With DSB, one can go without water change for 12-18 months at least (with reasonable load and feeding schedule) and will not have any problem with nitrate. Many people have done it. Water change in a DSB system is not use to decrease nitrate, at least for me.
With DSB, we do not need any LR at all for filtration. I don't have to cramp my tank with LR to filtrate the tank. Rock is needed for structures and beauty only. The DSB tanks (can) have plenty of room for corals and fish. We never know what some one choose to do with their aquarium, but I know that I can set up a reef tank with just sand fish and coral without LR and the filtration process will go on just fine.

We really do need to export phosphorous. My philosophy is to export phosphorous with any and all mean possible. This is why I don’t think that the phosphorous will build up in my tank at all, or at least for a long time.

Minh

 

[Elmo18]

im PRO DSB

Hi all. I'll chime in. I'm leaning towards the DSB idea. I've had several tanks running DSB and love it. I am not getting any nitrate readings whatsoever and untraceable ammonia.

Again, Minh as pointed out the advantages of a DSB. It helps to process nitrogen and does so with very little maintenance in my experience. Yes, while there maybe a phosphate reading, you can lower that by just having a refugium with macroalgae. The algae itself will suck up nitrates and phosphates.

Another reason is that it looks more natural to me to have a sandbed. This of course is the least important, although to some people it might rate the highest. It just doesn't look right with it sitting on "glass".

The sandbed provides small fauna which becomes food for corals and fish, and other invertebrates. This includes worms, pods, plankton, etc. Thus, it provides natural food.

What I hear most from people complaining from DSB is that it doesn't work, that nitrates are high, phosphates are high. One reason is you can't just dump Southdown sand or small particle calcium carbonate sand and expect it to work right away. I have used silica sand for sandblasting and calcium carbonate sand (right now my 75 gallon is half and half) and both have worked. The key thing is to make it "live" before stocking up on corals and especially fish. Patience pays off. I waited 6-8 months before stocking on anything and left the tank just with rocks, heater, and powerheads. During that time, critters from the rock migrated into the sand, and thus gave time to populate the sandbed. Albeit, it maybe a long time before stocking, you can buy infauna kits or just get a handful of sand from a fellow reefer. Then just wait. In order for the DSB to work, it must have critters to process the large pieces of food that the corals/fish have not eaten, etc etc. It must also be deep enough. You will know when you see oxygen packets in your DSB.

Other times people complain their DSB makes their tank look dirty. Yes, what grows on the glass/acrylic is cyanobacteria. This is especially true for newer tanks. However, it will also occur in larger tanks where pockets of bacteria or food end up and cause cyano. However, these come and go. If you dont like the way it looks, maybe cover it up with wood siding and blend that in with the rest of the stand? IMO, keeping the animals happy is number 1 priority. Looks come second.

My current tank (75 gallon) and other smaller tanks are all run skimmerless, relying only on liverock, macroalgaerefugium, and the DSB. I would recommend having a partition in your sump for a refugium, or a separate container/tank for the refugium. This serves many many helpful purposes. One, it allows you to grow macroalgae to reduce phosphates to low and undetectable levels.

Asise, phophorus is one of the building blocks of living matter. In fact, its present in every living creature and reef tank waters. Phosphorus only causes problems when it is in excess. Ok, so first it inhibits calcification/growth of coral (i.e. lack of coralline, new SPS growth) and second it will drive nuisance algae to grow like a forest. Macroalgae seems to be a natural way for absorbing phosphates in our tanks, and one of the easiest. They also use other nutrients in the process. Having a refugium to grow, harvest these plants help control algae growth in the main display tank. Studies have shown that Caulerpa racemosa is about 0.08% dry weight phosphorus and 5.6% nitrogen. Continually growing and harvesting macroalgae thus in fact remove phosphates.

Another reason people complain about DSB is the inconvenience of never getting enough flow for their SPS, or that their tanks become lagoonal because of it. This of course is true if you are trying to use surge tanks in shallow height tanks and other extremes. Seems like my sps are doing fine in 15-20x flow in comparison with tank size, and no sand is flying around in the water column. Flow placement and direction can affect whether sandstorms will occur. Albeit, if you are trying to simulate reef tops and surges, barebottom is the way to go.

Minh also pointed out another important point. He feeds heavily and gets no nitrate readings. The sandbed must be fed. There are living creatures in the sandbed that eats (i.e. the bristleworms, the copepods, amphipods, etc, spaghetti worms, etc.). Without feeding, they starve, die. They also do not reproduce much. I do not directly feed the bed, but only feed for corals and fish and in doing so, there are enough food that is uneaten that gets to the sandbed where hermits, snails, and sandbed fauna devour of it.

The disadvantages, or some of the bigger ones are: less volume of water/space for corals, sandstorms from super large GPH flow pumps, dirty. I can discuss those further, but they seem to be self-explanatory

IMO, if you maintain a DSB correctly (although i really haven't done anything much to my sandbed), I think overall it will be a benefit over barebottom. Again just from my experience and opinion.

- Ilham (aka Elmo)

 

[Elmo18]

Again, I forgot to mention, how deep is "deep enough?"

IMO 4-6" of sand is sufficient to be a DSB, consisting of oolitic, small grain particles. There are manycombinations people use...or just all Southdown playsand...which we can't really have access to in the Northwest. Not readily anyway.

- Elmo

 

[Elmo18]

This is what 3 lattes does to you....wel for me anyway... 3:30 am and still typin!

ok, g'nite.

- ELmo

 

[Scooterman]

......Having about one inch very course sb; I have to disagree about the bare Bottom statements above, .....

I would say that you do not have a DSB. IMO, having a thin coarse substrate is the worst of both worlds. Not enough to perform the function of a DSB and just collect detritus. Your conclusion is invalid because you do not have a DSB.

Minh

That was not the meaning of that statement, I consider a rather coarse thin SB easy to vacuum, thus removing waste but at the same time allowing for aesthetics of having a SB. Dr. Ron recently stated that having a remote DSB wouldn't work like having in the main display. Me personally, 4 to 6 inches of sand in the main display took up too much room, looked like we were looking inside the DSB and not from above, where most of the human looking is done, when done for admiring it's beauty. I had that DSB and chose to remove it, after a year and a half of the DSB, then removing it to what I have now, I love the way it looks now, I don't mind doing 4 to 6 week 25% water changes. I haven't noticed any increases in Nitrites or Nitrates and tested ammonia yesterday with a reading of less than can be measured with the Saliflert test kit.
Now with that said, if your willing to do the regular up keep that a DSB required and like the looks then I'd say enjoy but before you install it, make sure you plan to a good regimen for cleaning and up keep.

 

[mojoreef]

Good debate folks and welcome to the talk Ilham. Minh you are right a DSB will have the advantage in the processing of nitrates but a disadvantage in everything else..tough choice. On the water changes...I cant help ya thier..I have never done one (on purpose anyway ). On the choice of having LR or sand for looks that is an individual thing so no answer thier, but on the phosphates, good luck buddy .
Ilham I have some thoughts for you.

Again, Minh as pointed out the advantages of a DSB. It helps to process nitrogen and does so with very little maintenance in my experience. Yes, while there maybe a phosphate reading, you can lower that by just having a refugium with macroalgae. The algae itself will suck up nitrates and phosphates.

Ilham yep on the nitrates, no chance on the phosphates. Our test kits only measure inorganic phosphate which is very tiny compared to organic phosphates. If you are testing your water column and you have inorganic phosphates that means that you probibly have a ton of organic ones. You mention using a refugium with macro algae, two problems here. One is that the phosphates are locked into a never ending cycle in your DSB and will never be allowed to excape it to become available to your refugium. They will be bound up in either vegitation or animal or substraight, no chance on them being freed unless you start removing the bed. Second is that macro algae is not a very good export device. Because of its cell structure (very thin walled) it leaches out what it absorbs as it absorbs (ie if it absorbs 10ppm it will disasorb 7ppm at the same time) but I guess it is a plus, unless of coarse it goes sexual??.

The sandbed provides small fauna which becomes food for corals and fish, and other invertebrates. This includes worms, pods, plankton, etc. Thus, it provides natural food

Ahhh this is another urban legend. LR will produce the same critters (actually a more diverse ammount). In sand the ruler of this eco system is bacteria. and the bacteria from a dsb does not feed any corals or dusters and so on. They are attached and bound to substraight and are not going anywhere, unless of coarse a larger bug such as a worm or pod swallows or picks them of the sand. as per plankton..good luck..way to aggressive of an ecosystem. due some research on where plankton comes from..its not the sand.
Oh and the small bubbles you see in the bed arent oxygen its nitrogen gas.

Ok lets get into some of the other disadvantages not listed.
>Beyond nitrogenious waste it does not process anything.If stuff is not processed it stays..if it stay it sinks..if it sinks and thier is a bottom...it fills..if it fills it must be replaced. (real simple logic and every so called expert on DSB's say it)
>It does not allow for flow, which means that the detritus and the bacterial associated with it is not available for the corals and critters that happen to eat it, instead its stting in the sand. Also we can keep the corals free of food deposits which can and does lead to bacterial infections.
>It creates an endless phosphate cycle one that will continue to get larger and larger until the cycle is broken ( ie: remove the sand and/or the bacteria). yes I guess you could continue to harvest cyano (which I perfer not to), or you could plant macro in your main tank DSb ( which would turn it into one big refugium)
>the build up of phosphates will limit the growth of your corals (hard corals)
>The build up of phosphate will fertalize the zoox in you corals that have it. This will cause your corals to turn brown as Zoox are brown in appearance.
>Your DSB is a very diverse and populated ecosystem that has a huge demand on oxygen. Watch how quickly it sucks the oxygen out of the water column if the power goes out. Also this demand on oxygen with in the DSB will create larger areas that become anoxic (devoid of oxygen) this will greatly age the bed. Thier has been tons of studies that show this.
>if you have a problem in your say SB you can simply remove it with a quick syphoning. If you have the same problem in your DSB you can you must suffer through it.
>You are very limited to the creatures you can keep. You are not alloowed to keep any critters that may eat the precious bugs. Ie: most star fish/gobies/ some shrimp, wrasses that dig to sleep, and so on and so on.
> because of recruitment and the limit to the size of the bed you must continually replenish the critters. A well seeded DSB (with all the critters) will demish quickly and become an ecosystem dominated by usually just one type of critter (9 times out of 10 its a worm). Survival of the fittest.
> A DSB in no way resembles a natural reef system, it trys to mimic a lagoonal system. So if you want to try to create a lagoonal system (vast amounts of sand with the odd coral bombies) its a good thing. If you are trying to recreate a reef, skip the sand. Thier is a reason you dont see sand on a reef top or a fore reef and so on.
>one event such as a powerhead dropping or a fish diggin to deep or anything simular and everything is dead, throught the releae of sulfide/sulfate/methagen and so on.

All this work and all these risks to create a complex ecosystem for the removal of nitrates. When if you simply syphoned/skimmed out the waste prior to its breakdown you could avoid it all.

Anyway I am babbling now, sorry for the long post.

Mike

 

[Scooterman]

AHH, THAT IS A GOOD POINT!

Flow, Funny thing now, I see poop floating around a while, even disappears behind the rocks but with the flow I now have, that poop will spin around from all over. Nothing settles down anymore, when I vacuum, I suck the poop out by the time I finish vacuuming, I've removed about 25% of the water, so then I replenish it with new water. Whatever the skimmer misses, I suck out the rest (well most of it).

 

[Elmo18]

I love debates!

This kinda sux, but I dont want to rewrite what i just wrote because apparently it was on the screen too long, and when i submitted it, it asked me to log on. Then everything was gone.

I rest my case. Read this article:

http://www.advancedaquarist.com/issues/sept2002/chem.htm

andn download this free PDF from the Journal of Marine BIology:

http://www.botany.hawaii.edu/Bot482/Kaneohe Bay algae N-P Larned Mar Biol.pdf

Ilham yep on the nitrates, no chance on the phosphates. Our test kits only measure inorganic phosphate which is very tiny compared to organic phosphates. If you are testing your water column and you have inorganic phosphates that means that you probibly have a ton of organic ones. You mention using a refugium with macro algae, two problems here. One is that the phosphates are locked into a never ending cycle in your DSB and will never be allowed to excape it to become available to your refugium. They will be bound up in either vegitation or animal or substraight, no chance on them being freed unless you start removing the bed. Second is that macro algae is not a very good export device. Because of its cell structure (very thin walled) it leaches out what it absorbs as it absorbs (ie if it absorbs 10ppm it will disasorb 7ppm at the same time) but I guess it is a plus, unless of coarse it goes sexual??.

Too many things in that paragraph that i disagree with. The major one being macroalgae is not a very good export device. Totally disagree there. First off, skimming itself will remove much organic phosphates before it has a chance to break down into inorganicphosphates. Inorganic phosphates doesn't bind into the air bubbles particulates. The point is to harvest the macroalgae. If you guys....still...dont believe macroalgae absorbs phosphates...well...I can't make you.

This is a fact, and will always be.

- Elmo

 

[Elmo18]

I'm also another believer in if it works, dont fix it.

My tanks have been running for several years, no problems, corals growing, whatsoever, etc etc.

I also know that berlin style German tanks have run barebottom and have no problems whatsoever. So, both work, I prefer the sandbed method.

-Ilham

 

[Minh Nguyen]

My tank did verywell with DSB. I don't ahve algae problem and my SPS is extreemly colorful and fast growing.
There are many ways one can use o export nutrients, Magcro algae in high light situation is very effective.
Also, doesn't everybody know that poop is food for many animals? I can tell that my LS is full of animals. I seee them spawn all the time. I ma nost sucessful with DSB, and very happy with it.
Minh

 

[mojoreef]

The major one being macroalgae is not a very good export device. Totally disagree there. First off, skimming itself will remove much organic phosphates before it has a chance to break down into inorganicphosphates. Inorganic phosphates doesn't bind into the air bubbles particulates. The point is to harvest the macroalgae. If you guys....still...dont believe macroalgae absorbs phosphates...well...I can't make you.

Elmo I am not saying macro algae does not remove phosphates. Algae is an export method for sure. I stated that because of the cell structure of various algaes they leak a percentage of what they absorb as they absorb, but it is still a plus and viable. Skimming is a good way of export phosphates that are associated to DOC's and such. but they have to be available to the skimmer in order to do the exporting.
What happens in the recycling system of a DSB is that available phosphates are bound by algae (usually cyanobactor). This is why most DSB advocates say cyano is a good sign of a healthy DSB. As the phosphate are used up by the cyano (or other algaes such as hair, dino's and so on) they begin to die off. This creates a bloom in the bacterial population that begins to feed on the decaying algae (this is the cycle). Once the vegitation begins to be reduced the bacterial population begins to die off for lack of food. With thier dieing the phosphate is once again released and quickly bound by algae once again. All this happens with in the layers of the top of the DSB and the surface area, because of this it is not available to the skimmer to remove.
If you look over the links you posted you can see that the Sediment beds are reseviors for phosphate and macro algaes grow best when they root or hold fast into the pore water of the bed. On the link to the hawaii study look on page 12. it should answer some questions.
Folks I am also one that believes that if it aint broke dont fix it. And I am not saying that any one with a DSB that is currently working well to remove it. A time will come when you can make that call. What I am trying to say is that thier is a misunderstanding on what a DSB does and does not do. As long as anybody has both sides of the story they can make an educated choice. So that is what this thread kind is.

Mike

 

[mojoreef]

Also, doesn't everybody know that poop is food for many animals?

Yep Minh I think most have that understanding. Now if the detritus is suspended in the water column through the use of strong flow then it is available to the thigs that may eat it. But if it is stuck in the sediment bed, well....then it is providing food to things that live in that bed.

Mike

 

[Minh Nguyen]

Also, doesn't everybody know that poop is food for many animals?

Yep Minh I think most have that understanding. Now if the detritus is suspended in the water column through the use of strong flow then it is available to the thigs that may eat it. But if it is stuck in the sediment bed, well....then it is providing food to things that live in that bed.

Mike

That is what I want. The bed is far from having only bacterial. I can tell you from personal experience that the flesh mass in the sand, only counting larger worms and animals, rival the mass of all the fishes in my tank.
Minh

 

[mojoreef]

For sure Minh the life in the areobic zone should be quite alive with all sorts of things beyond bacteria. Thats what makes that first inch or so, so attractive. I guess it boils down to what we want to keep in our reef tanks, worms are ok I guess, just not something I have a real interest in keeping or propagating.

take care

Mike

 

[Minh Nguyen]

My worms go all the way down, even to 10 inches in fine South Down sand. Some how, they must have mechanism to get O2. From the worms that have holes against the glass, they have an undulated movent of their body in their holes. This must cause flow of water down to the bottom. All I know is that the sand is full of worms down to the bottom. Less on the bottom than on top but there are lots of worms thatlive deep down there where there should be no O2 other than what the worms some how bring it down.
Some of these worms are colorful some completly black others are pinkish/red. It is the baby worms, gametes, eggs that I want. That is what feed my corals.
Minh

 

[mojoreef]

yes Minh thier are certian worms that have the ability to basically hold thier breathe and dive down for bacterial food. These are the deeper tracks you see. They are very important in the migration of detritus down and nitrogen gas up.
Here is a thread on RZC where we are looking up a variety of studies/experiments and so oon done on sediment beds. t should make for a good read for DSB users.
http://reefcentral.com/forums/showthread.php?s=bf7406ebb0636b62c39b63c416e0ddae&threadid=263482&perpage=25&pagenumber=1


Mike