Are Deep Sand Beds, DSBs, dangerous to use in a marine aquarium?

[Randy Holmes-Farley]

What do I do about the "ticking time bomb" of nutrients?

As long as it keeps ticking, you don't need to worry

 

[billsreef]

Yes, you can plant seagrass in your sand. The typical turtle grass needs a bare minimum of 4 inches, preferable 6 or so...so a truly deep sand bed

 

[Lavoisier]

Also, could I plant a patch of sea grass in my sand? Wouldn't that use the phosphates and maybe some fish can graze on it? And what do you think about having a single gobie? Would love to see it nibble on worms and stuff.

phytoremediation--The technique of planting trees, grasses, or other vegetation in order to remove contaminants in the soil or the groundwater through accumulation (and sometimes degradation) in plant tissues, or to promote their microbial degradation or immobilization in association with plant root systems.

 

[3D-Reef]

For those of us who don't get the chance too go "mucking around" in the mud,looking at the various worms and such.Are the worms in the muck/mud (and I know there are a thousands of different kinds) different than the worms out on the reef(in carbonated sands),or,are they pretty much the same thing/size/function ect.?

 

[billsreef]

For those of us who don't get the chance too go "mucking around" in the mud,looking at the various worms and such.Are the worms in the muck/mud (and I know there are a thousands of different kinds) different than the worms out on the reef(in carbonated sands),or,are they pretty much the same thing/size/function ect.?

There are different worms in the muddy muck, but of course related worms can be found in typical reef sediment. The real point in this thread for involving the worms found in the anoxic back marsh muck is to show that, yes, indeed there are a whole host of critters evolved to live in deal with anoxic sediments...something some people claim doesn't happen, despite facts

 

[rounder45]

Don't forget the tardigrade...

 

[JPMagyar]

We need not "believe" that organic matter will sink into a DSB. "Belief" should be reserved for religion. Not science. The basic laws of physics tells us that organic matter sinks. Organic matter is typically heavier than water. Therefore, it sinks. We do not need a dedicated scientific experiment to show this. The science involved is well known and well understood. To "believe" differently is to simply be wrong.

If you must have an experiment to show this process, it's simple. Take two white buckets and a gravel vac. Siphon water from the mid water level of an aquarium, into bucket "A". Then siphon water through an aged Shemik style DSB, using the gravel vac, into bucket "B". We can not see through organic matter. The bottom of bucket "A" should be clearly visible due to the lack of organic matter. Bucket "B" will be so choked with rotting organic matter that the bottom of the bucket is not visible. The sand was clean when it originally went into the aquarium. How did the organic matter get in the sand? . It didn't just magically appear. It settled, and accumulated there due to the well know laws of physics. This isn't arguable. It can not be disputed. It is fact.



Again, this is well known and well understood science. One organisms waste is anothers beneficial nutrients. This is the process that makes life possible on this planet. Our waste is toxic to us, but not to some other organisms. We must separate ourselves from our waste or die. If your kidneys fail, you're dead, because you are no longer able to separate yourself from your waste. If you relieve yourself in your bedroom, and allow your waste to accumulate there, you're likely to get sick and die. If you relieve yourself on your lawn, you're likely to have some lush green grass, because the grass is able to utilize your waste as beneficial nutrients. If we force our pets to live in a tiny glass box with six inches of their own waste accumulated on the bottom, they're likely to get sick and die. This is nothing new. It's well understood. We clean the bottom of every other small container where we keep living animals. Hamsters, birds, snakes, humans in jail............... you name it. If we do not remove an animals waste from the small container where they live, they are highly likely to get sick and die. This is fact. It is not arguable. This is not a "hypothesis". This is not a theory. This is well known fact. To "believe" otherwise is simply absurd.




Who are these "noted scientists", and where is their work?
There is no scientist, worth their salt, that would make such a statement.
If the flow is slow enough to allow the grains of sand to remain stationary on the bottom of the tank, it is also slow enough to allow particles of organic matter to settle and accumulate there as well. You would have to increase flow, to the point that inorganic particles could not remain stationary, to prevent organic particles from becoming stationary. Stationary particles of sand obstruct flow, slowing it to the point that organic particles carried into the sand with that flow, settles and rots. The only way to prevent this, would be to increase flow to the point that sand itself was no longer stationary.







What is your definition of a "healthy" DSB? And healthy to who?

It's been explained before. A sand bed that is deep, need not be "unhealthy". We simply need to keep it clean. A sand bed, as Shemik describes it, where we allow "sludge" to build to the point that it supports hundreds of thousands of sludge eating organisms, will becomes unhealthy for the pets we purchase.





Why is that relevant? We know that the more biomass we have in a system, the harder we need to work to keep the system clean and healthy. The lower the biomass, the longer the tank will remain healthy without our intervention. We really don't need to put a number on the amount of biomass produced from feeding "X" number of fish. We simply need to understand the importance of keeping that number as low as possible.



No, but again, it's really not relevant.




Not any more different than the rest of the animal kingdom. The waste produced will vary from species to species and from day to day. The waste I produce today will be different from the waste I produce tomorrow. I seriously don't see where this is relevant though. All of this waste material contains many different elements and compounds. As this waste breaks down, the substances it contains will be altered and released back into the environment. These substances are beneficial to some, and toxic to others. This is one of the reasons we have different habitats in nature that support different forms of life. Mangrove swamps have high concentrations of these substances, due to the large amount of rotting organic matter in the sediments. There are times you can smell a mangrove swamp from miles away. The organisms found in mangrove swamps differ greatly from those found on healthy, growing, coral reefs. The concentration of substances released through decomposition are very, very, very, very, very, low on these healthy coral reefs. This should be a HUGE red flag to anyone attempting to keep coral reef creatures in a tiny glass box. Keep large amounts of rotting organic matter in the tank, and you create something that resembles a mangrove swamp. Remove rotting organic matter and you're more likely to create something that resembles a healthy, growing, coral reef.



Yes. The rate of accumulation will, or can, differ greatly from one system to another. However, the rate of accumulation is irrelevant. If I drive to work a 50 MPH, I'll get there quickly. If I drive 5 MPH, I get there slowly. It doesn't really mater because I end up at the same place. If I accumulate one cubic CM of rotting organic matter in my sand per week, it may take quite some time before it becomes unhealthy for my pets, or causes me to invest in a larger skimmer. If I accumulate ten cubic CM's of rotting organic matter in my sand per week, it will become unhealthy much faster. I don't need to have a number to represent the rate of accumulation. I simply need to understand that I need to limit that accumulation, and/or take steps to offset the negative effects of that accumulation.


We know that it accumulates, not only because we see it with our own eyes, but because we typically feed at a rate that exceeds the rate of decomposition. In other words, if we feed a cube of food, we typically feed another cube before the first cube has a chance to completely decompose. A portion of that food will end up in the sand bed even if we have an incredible filter system.

Nature is great at supporting massive amounts of life, and creating very nutrient rich environments, with very little nutrient inputs from outside sources. In our system, what starts out as a little detritus in the sand bed, can become a nutrient laden swamp, if we do not intervene to stop this process. Bacteria will take up nutrients from that detritus and reproduce. Bacteria can be short lived. When they die, their tissues are added to the rotting organic matter in the sand along with the small amount that gets there through the food we feed. Now the living bacteria are utilizing nutrients that originate from the foods we feed, and the tissues of their dead relatives. As this process grows, the amount of nutrients being released into the system water grows. It begins to fuel algae and microbial growth in the rocks above. When these organisms die, they fall into the sand, where they rot and fuel more growth/reproduction. As the amount of organic matter grows, it begins to support larger animals like worms, and mini crustaceans/pods. These organisms don't typically live long either. They grow, reproduce, and die, just as the algae and microbes do. Through this process, nature is able to recycle nutrients in one area, increasing the nutrient content of that area, even when the input of nutrients to that area is very low. This is clear to see in photos of Shemik style DSB's. There is an abundance of life in these sand beds. Everything from cyanobacteria, worms, pods, algae, and countless little critters not viable with the naked eye. This proliferation of life could not be possible if it relied solely, and directly, on the food being added to the aquarium on a daily basis. It's only possible due to natures ability to retain and recycle nutrients in one area. In a Shemik DSB system, on day one, everything is clean, and the nutrient level of the system is low. As time progresses, the nutrient level within the system continually climbs. The common scenario in these systems is for the filtration and maintenance to cope with this pollution for a period of time. The health of the system is constantly being degraded, but the filtration and maintenance handles it. Eventually, the system reaches a point where the production of harmful substances from rot and decay overwhelm the filtration's ability to keep those levels low. This is when animals die. People declare the system is suffering from old tank syndrome, and needs to be started over. Often, the hobbyist "belief" in this system is so strong, they break down the system, and rebuild it, doing the exact same thing again. This only leads to more animals dying, and thousands of dollars needlessly spent.




While hydrogen sulfide is a reasonable concern when talking about harmful substances from decaying matter, it isn't needed to cause illness and death in our systems. Any number of elements, compounds, or combination of substances released/produced through decomposition can reach harmful levels when you have six inches of rot and decay on the bottom of the tank. Most elements are at trace levels on coral reefs. Some down to the parts per billion.




You have stated that this is not evidence proving DSB's are beneficial, yet you keep bringing it up, and even posting pic's of tanks with DSB's, as if it proves something. It does not.

Most people would agree that dumping liquid fertilizer, full of nitrogen, phosphorus, and heavy metals into a reef tank would be a bad idea, and put the lives of the inhabitants at risk. However, I could hook up a dosing pump to dose such a fertilizer into my system, and still have a seemingly healthy and thriving reef display. I simply need to employ methods to remove that fertilizer at a pace that keeps the concentration of harmful substances below problem causing levels. The question is, why would I do that? The fact still remains that such liquid fertilizers would be harmful to coral reef tanks. Six inches of rotting organic matter on the bottom of a tank will release fertilizers like nitrogen, phosphorus, and heavy metals. Just like the liquid store bought fertilizers. So, the question is, why would I put such a sand bed on the bottom of my tank?




No. We can not say that. The fact that they have a DSB, and all their animals haven't died, is not evidence that a DSB works. Shemik and his disciples have made some outrageous claims about the magical abilities of their DSB systems. If a DSB does not preform these tasks, they do not work. If I pile up a bunch of scrap metal in my front yard, and claim it to be a rocket ship to the moon, can I claim that it works if it can not fly to the moon? Of course not. It's just a pile of junk in my front yard. This DSB does not perform the tasks claimed of it. Therefore, it does not work. It doesn't matter that a DSB hasn't killed every living creature in some tank somewhere. It still does not work. It's still nothing more than a six inch pile of rot and decay full of worms and bugs.


Peace
EC:beer:

I can't believe I missed this and never responded!!

It's still nothing more than a six inch pile of rot and decay full of worms and bugs.

Show me a single scientific paper that shows this to be the case in 10 year old DSBs.

I do not have the time to tackle the "whole enchilada" right now,but maybe I can take this piece meal. My quick summary is you have a bias and make assumptions about aquariums that are simply not proven nor are they born out by reality. The simple fact that healthy DSBs exist negates every comment you made. I keep repeating this and people with experience in the science of waste try to compare what happens in waste plant situations to reef tanks, but what little science does exist regarding sediments surrounding actual reefs shows that the concept of waste build up simply isn't happening this plus the fact that home reefs can be maintained for long periods belies every word of your reply.

 

[JPMagyar]

We need not "believe" that organic matter will sink into a DSB. "Belief" should be reserved for religion. Not science. The basic laws of physics tells us that organic matter sinks.


Peace
EC:beer:

OK lets take it in order. . .

You take my words too literally. Science shows us that real world reef sediments are NOT filled with waste. What scientific papers have shown the rate of accumulation of waste products in home reef aquarium sediments? Answer: not a one. Yes waste sinks, but we as aquarists are using a myriad of methods to export waste and one part of that is the microbial breakdown of nitrogenous and phosphorous organics which then become amenable to removal by one or more methods.

How this process works in a home aquarium has not been studied and until it is you can not say unequivocally that waste is "sinking" AND remaining in a DSB.

If it did then DSBs would ruin all tanks and that is simply not happening; so in this first case you are clearly wrong.

 

[JPMagyar]

But,

before I go further with dissecting your reply from long ago let me ask your opinion on the central tenet of this thread.

Do you believe that DSBs are ticking time bombs and should never be used in a home reef type aquarium?

 

[billsreef]

Joe,

You have far more patience than I do

 

[Brummie]

Are Deep Sand Beds, DSBs, dangerous to use in a marine aquarium?

But,

before I go further with dissecting your reply from long ago let me ask your opinion on the central tenet of this thread.

Do you believe that DSBs are ticking time bombs and should never be used in a home reef type aquarium?

Wouldn't this also be pertinent to live rock? Don't know about everyone else but the majority of my live rock is subjected to very little or nearly no flow, the porous structure is probably chocked full of organic stuff (and things eating it). Presumably, due to the rock being basically a less mobile version of a sand bed, the same conclusions could be reached.

 

[elegance coral]

I agree that if you have algae on the sand it is an issue. Otherwise, I don't see it as any concern. Who cares about the "overall content"? If it isn't impacting creatures in the water column, it seems a minor point to me.

Posted by elegance coral
Phosphate can be cycled very tightly. Moving from organic to inorganic and back many times before it's eventually released into the open water as inorganic phosphate and removed by the means you describe. This tight cycling can fuel unwanted organisms like algae, and hinder the growth of wanted organisms like stony corals, even when our test kits are telling us we're maintaining a very low inorganic phosphate level.

If we have an abundance of rotting organic matter in our sediments (rock and sand) the phosphate being released can be utilized by algae growing on those sediments. When that algae dies, (if its eaten by snails or not), it returns to the sediments as more rotting organic matter to fuel more algae growth. This process can be repeated many, many times. None of this phosphate will be detected by our test kits, or be removed through filtration like GFO, but it does have the ability to effect the corals that we try to grow on these same sediments.

 

[elegance coral]

x2000

If the overall content (including what's in the biomass and sediment) was such a problem, reefs wouldn't exist as we know them.

what little science does exist regarding sediments surrounding actual reefs shows that the concept of waste build up simply isn't happening.........

 

[elegance coral]

Show me a single scientific paper that shows this to be the case in 10 year old DSBs.

http://www.ronshimek.com/deep_sand_beds.html

This is the closest we have, and likely to be the closest we'll ever have, to the paper you're asking for. It was done by a scientist, that did extensive research, then wrote a paper about it.

Here's a quote from that paper.

"I have done sampling to measure the abundances found in the 45 gallon tank I mentioned earlier, and the number of animals larger than half a mm, or about one fiftieth of inch, in that tank ranges from 90,000 to 150,000 depending on what part of their population cycle the various species are in"

So, we have ~100,000 small animals that feed on rotting organic matter, living in the sand bed of a 45 gallon aquarium, but there's no rotting organic matter in the sand for them to feed on???????? This is like saying there's 100,000 deer in a forest, but no vegetation for them to feed on. Nature doesn't work that way. If we have 100,000 poo eating critters, we must have an abundance of poo to support them. This isn't even arguable. It's simply the way nature works. You can not support large populations without large amounts of food.

My quick summary is you have a bias and make assumptions about aquariums that are simply not proven nor are they born out by reality.

Can you quote one of these assumptions not born out by reality, or is this just a baseless personal jab with absolutely no foundation to support it?

The simple fact that healthy DSBs exist negates every comment you made.

We've been over this multiple times. What is a "healthy" DSB, and healthy to who?

The fact that someone has maintained a DSB and managed not to kill every single creature they added, is not evidence that the DSB is performing some beneficial task. I don't understand why you keep insisting that it does.

 

[elegance coral]

Do you believe that DSBs are ticking time bombs and should never be used in a home reef type aquarium?

I don't like the term "ticking time bomb", and I've never used it. That term simply causes people to develop the mindset like Randy has below.

What do I do about the "ticking time bomb" of nutrients?

As long as it keeps ticking, you don't need to worry

From the moment that first tiny particle of organic matter settles into the sand and begins to rot, the DSB begins having a negative impact on the system. The more rotting organic matter it contains, the worse its effects become. It's not as though the DSB performs some beneficial task and works all kinds of miracles, then one day, for no logical reason, BOOM:blown: , it explodes killing everything in its wake. It's a slow and steady nutrient enrichment of the system that often leads to a decline of the reef and it's inhabitants, just as nutrient enrichment does on the reefs in the wild.

 

[Fredfish]

So, we have ~100,000 small animals that feed on rotting organic matter, living in the sand bed of a 45 gallon aquarium, but there's no rotting organic matter in the sand for them to feed on???????? This is like saying there's 100,000 deer in a forest, but no vegetation for them to feed on. Nature doesn't work that way. If we have 100,000 poo eating critters, we must have an abundance of poo to support them. This isn't even arguable. It's simply the way nature works. You can not support large populations without large amounts of food.

There is a difference between having lots of organic content available to sand bed organizms, which is quickly consumed, and having a large accumulation of unconsumed organic material (non refractory) in the sand bed.

Lots of people feed an abundance of food to their fishes and corals. Nobody considers that a ticking time bomb. In fact, many consider these feeding levels essential to the health of the tank. Everybody finds a way to manage the resultant organics. Having a thriving sand bed is just another tool to manage nutrients. Nothing more, nothing less.

Out of curiosity, what percentage of the total mass of living organisms in an aquarium does 50,000 sand bed critters represent? is it 2%, 10%, 50%? If we are going to fear these creatures, should we not quantify the threat?

We've been over this multiple times. What is a "healthy" DSB, and healthy to who?

I love phylosophical discussions. If you ask the same question regarding the portion of your tank above the sand bed, what answer do you get? Do you get to a single anwer that everybody, or even a significant number of hobbyists can agree on? Should we compare it to healthy organisms and systems in the wild?

The fact that someone has maintained a DSB and managed not to kill every single creature they added, is not evidence that the DSB is performing some beneficial task. I don't understand why you keep insisting that it does.

If we apply this same logic to any other piece of equipment or system used in/on our tanks, what do we come up with other than: "it works for me, but I have no idea if it is beneficial or not."

For instance, what proof is there that skimmers are performing some beneficial task. Sure, lots of people use them and manage not to kill every single creature added, but where is the proof that skimmers are beneficial?

I would submit that if you can maintain a tank with similar "health" to a non deep sandbed system, that sandbeds are as 'beneficial' as systems with other nutrient control systems like skimmers, and various chemical media.

 

[billsreef]

EC,

You are doing that random dot connecting bit that TMZ talked about. For instance you pulled out two quotes from Joe and myself, without adding any commentary. Based on your comments in the overall thread, I expect your trying to make them out to be contradictory statements, yet they are in fact are not contradictory. We do know there are a level of nutrients and critters in the sediments of the reef, and we do know those same reef sediments are not accumulating and turning the reefs into mucky eutrophic zones

x2000

If the overall content (including what's in the biomass and sediment) was such a problem, reefs wouldn't exist as we know them.

what little science does exist regarding sediments surrounding actual reefs shows that the concept of waste build up simply isn't happening...

You also seem to keep thinking all that tight recycling will turn a tank into an nuisance algae filled, due to crash system...while ignoring that not only does this not automatically happen in a DSB system, but it also happens quite regularly in every tank system ever known...so it's an argument that pertains to all equally

 

[tmz]

Can you quote one of these assumptions not born out by reality, or is this just a baseless personal jab with absolutely no foundation to support it?

This is not a personal jab;just a clarification of what appears to be an overstatement of opinion as fact from post 509.The context was in a response to Bill's statement regarding" bacteria on up"

They are irrelevant to the total P content of our glass boxes, but they are a major contributor to the "P that can cause issues in our tanks". They take organically bound P, which is harmless, and convert it into inorganic P, which causes issues in our tanks. They do the same with other elements that could potentially cause issues in our tanks, like heavy metals. The more of these types of critters we have, the more inorganic P they're producing.

Maybe some organisms do at some stages of excretion but they also produce exudates ,larvae etc,that are organic; they may also take up inorganic P .
I'm skeptical you can support that statement as it is. Bacteria assimilate inorganic P as far as I know converting it to organic P for example They take up some metals too. Some other organisms do as well.Sponges are another known prime example of organisms that take up inorganic P and release organic P.

 

[tmz]

Tom don't push RUGFs. I like having the oldest tank on here especially with never having any problems. This thread is over 500 posts long. how many problem RUGF filter threads have you read? Have you ever heard of a RUGF failing? I think not.:lolspin:

I don't know of any other operating RUGF systems;so it's 1 for 1
Seriousness or not aside, that's the subject of lots of recent studies on denitrification in carbonate sand as a result of the type of advection an RUGF would generate (ie direct flow through the sediment)

Oh, I"m serious. I think the fluid dynamics have been largely overlooked in many of the arguments made by some throughout the thread. The upwelling occurring from advection on reef is ignored by at least one poster who strongly advocates stirring the bed deeply arguing it will move organics up and out somehow'ignoring his own concept of how gravity works. I think more orgnics will just settle in deeper areas where bacteial activity will eventually lead to anoxic conditions and sulfide production with deep stirring.

I strongly disagree with Paul that NO3 at 40ppm is a farcical concern for many corals ;nonetheless, upward flow through a coarse substrate with less clogging might be an improvement over largely inactive areas of seep sand.

 

[Fredfish]

...

I strongly disagree with Paul that NO3 at 40ppm is a farcical concern for many corals ;nonetheless, upward flow through a coarse substrate with less clogging might be an improvement over largely inactive areas of seep sand.

I would expect that how active or inactive an area in the sand bed is depends entirely on how well populated that bed is.