Why don't intermediate depth sand beds work?

[JPMagyar]

Plenty of anecdotal evidence noted by experienced hobbyists running ULNS have shown that tanks devoid of nitrate and phosphate (unmeasurable by hobbyist list anyway) result in poor coloration when combine with a minimal feeding regimen. An increase in feeding (or a decrease in carbon dosing/GFI) usually remedies this situation.

My tank has no measurable nitrate or phosphate. My corals are extremely colorful. Therefore Nitrate and Phosphate can NOT be the limiting factors.

Also if nitrate and phosphate were the limiting factors then an experiment could easily be devised where in nitrate is added from zero to x% and the change in growth rate for a coral would be measurable. I am certain that increasing nitrate on the Great Barrier Reef would not result in an increased growth rate of coral.

It is assumed in ULN systems the color change is from low nitrate and phosphate. It is possible the additives or lack of microscopic algae or stripped out strontium or numerous other reasons are the cause of the color change that people see,

BUT

if you want to respond on this topic again I'm very happy to start another discussion I would simply suggest you post a link to a new thread for us to jump to and remember I'm in no way questioning anyone's intentions here. I just like a good discussion :beer:


Joe

 

[power boat jim]

Because we know from research in waste treatment plants that bacteria exist that can live off such toxins as hydrogen sulfide. Do they exist in a DSB? Are there other bacteria that live in anoxic conditions that eat phosphate and do those bacteria live in a DSB? (P.S I challenge you to find the paper that shows that such bacteria do exist because in this case there is some research on the topic)




Show me one scientific paper where in DSBs or equivalent were tested in a controlled environment using proper scientific methodology and were shown to have released toxins. This is the heart of my complaint regarding your comments.




What works? How a DSB releases toxins? Where? Show me the "known science". What do you mean by known science? Look below for what scientific method means and see if you get at what I'm arguing.








Perhaps this is where you and I can simply agree to disagree. You are calling this statement "basic science". To me science means, use of scientific methodology.


Scientific Method (Wikipedia):

The scientific method (or simply scientific method) is a body of techniques for investigating phenomena, acquiring new knowledge, or correcting and integrating previous knowledge.[1] To be termed scientific, a method of inquiry must be based on empirical and measurable evidence subject to specific principles of reasoning


In the case you just listed you are saying an aquarium sand bed can be stirred up and the resulting cloud of detritus can kill it's inhabitants. Show me where this has been tested and explained. I stir up my tanks and create clouds of mess all the time, and I don't lose any corals. What is the mechanism you are claiming causes death? Lack of oxygen? Toxin release? If toxins what toxins were involved? Did they come from the sand bed or were they introduced through daily additives or food or aerosol sprayed in the room. Just because someone stirred a sand bed and corals died is not proof that DSB are toxic. This is science. No one has studied this because it costs money and time. It is taken as fact by many because it seems logical. It is NOT science.












This statement was made regarding "poo". Poo means feces. Feces do not collect on the bottom of a tank because it biodegrades rapidly into other organic and inorganic material. So to say "poo" collects on the bottom of a tank is patently false.





Exactly, and some genuine SCIENTISTS have posited logical THEORIES incorporating other scientific research as to why a DSB may be one method of controlling waste in an aquarium.


Here are some questions about DSB that perhaps you can answer.

1) What is the precise list of toxins that exist in all DSBs after 5 years?
2) How much of those toxins exist in relation to total system volume?
3) Does a 5 year old DSB release toxins and if so by what means? Dissolution? Ionic exchange? Gaseous release?
4) Do the toxins found in a DSB depend on system inputs, and if so how do the inputs change the toxins?




DSBs MAY be dangerous, and some anecdotal evidence exists to support this hypothesis, but this has never been proven through scientific method.



Joe :beer:

http://reefkeeping.com/issues/2005-12/rhf/index.php

Read this and it will answer SOME of your questions. There is alot of research out there. I found this in only a couple of minutes. If you look around Ill bet you could find answers to nearly all your retorts/ questions. But be prepared, many of the answers only seem to lean in the direction sandbeds can easily ruin a tank through detritus build up (poop) and releasing toxins when the sand bed is disturbed.

 

[Gary Majchrzak]

absolute zero PO4 (as measured by my Hanna colorimeter) had a detrimental effect on many of my corals in the past. You wouldn't want absolute zero PO4. I think it can be a limiting factor for certain critters

The problem with "nutrient" discussions is that everybody's idea of what is a "nutrient" is different. Not only that, but not all coral (and animal) species utilize the same "nutrients".

FWIW I would run my "SPS type" reef aquarium bare bottom except that (IMO/IME) some substrate in the aquarium IS a good thing simply because it DOES help generate certain items that some reef animals consume.
But I never let it get unmanageable with detritus buildup.
Maintenance is key.

 

[JPMagyar]

.

Jim,

Trust me when I say I have read nearly everything out there on the topic and the questions I pose are not for me, but rather just to show what it means to be scientific.

Here is a quote taken from the article you referenced. The authors are very careful to distinguish between the known danger of hydrogen sulfide and the HYPOTHESIS that a DSB may pose a danger.

Sometimes aquarists have run into problems when trying to remove a sand bed containing hydrogen sulfide. In some cases, corals and other organisms have died as a result. Whether these resulting deaths were from hydrogen sulfide or other causes is impossible to say, but it is a reasonable hypothesis, and one that can provide some potential preventive measures that will be discussed below.

A DSB MAY be dangerous. It remains yet to be proven scientifically.


Joe :beer:

 

[JPMagyar]

To anyone interested in pursuing this discussion/debate, I have a proposal.

I feel that the discussion so far is ill defined and could benefit from some focus so I think it would be great to start a new thread specifically geared to this topic. Therefore, I would urge folks to come join me in a new thread:

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

 

[power boat jim]

Jim,

Trust me when I say I have read nearly everything out there on the topic and the questions I pose are not for me, but rather just to show what it means to be scientific.

Here is a quote taken from the article you referenced. The authors are very careful to distinguish between the known danger of hydrogen sulfide and the HYPOTHESIS that a DSB may pose a danger.




A DSB MAY be dangerous. It remains yet to be proven scientifically.


Joe :beer:

That might be true. However, if an experiment or a condition can be repeated using the same conditions by numerous parties and the same results are incurred, that is a good basis for fact. Here I believe all we are saying is detritus builds up in the sand, it decays eventually producing H2s, the sandbed is disturbed releasing a toxic low pH gas into the tank possibly killing inhabitants. All of this has happend and certainly could be made to happen in a lab if someone really wanted to spend the time.Which part of this hasnt been or cant be proven scientifically many times over?

Im, just looking at the chain of events, all them are solid scientific fact. I believe you want numbers, times and levels put to them? am I correct?

I believe the author didnt make the connection since that was not in the scope of the paper. He did, in my opinion leave enough evidence that its a given, sandbeds under the right conditions, can certainly be a hazard.

 

[Gary Majchrzak]

the bigger picture

the bigger picture

Joe- I'd love to join that DSB thread you linked to but the bottom line is that a MARINE AQUARIUM ITSELF might be dangerous to marine life.

Again, it's a maintenance issue- and what type(s) of animals you keep.

 

[gbru316]

I agree Gary. I don't think anyone is saying DSB's are inherently dangerous, rather, that they CAN be, given other factors. The same can be said for many things we, as reef hobbyists do, such as carbon dosing, hydrogen peroxide use, phosphate dosing, etc.

I have no doubt a properly maintained DSB can be effective, but my definition of "properly maintained" is far different than the industry standard, "hands off" DSB approach.

JP: I was referring to coloration, not growth in ULNS systems.

 

[Nano sapiens]

What nutrients are needed to "feed" SPS, and what research has shown this?


Joe

'gbru316' has answered this, but I'll add this link for a more scientific view:

http://www.coralscience.org/main/articles/nutrition-6/how-corals-feed

An excerpt from the article:

Unfortunately, photosynthates alone are not sufficient to build animal tissue2,4-9. These elements are ingested by corals by removing particulate organic matter (plankton, detritus) from the water, and by absorbing dissolved molecules. Heterotrophy is essential for all corals and can meet up to 100% of the daily required energy in corals which are bleached or inhabit deep or turbid waters1,12-18.

 

[Nano sapiens]

What nutrients are needed to "feed" SPS, and what research has shown this?


Joe

'gbru316' has answered this, but I'll add this link for a more scientific view:

http://www.coralscience.org/main/articles/nutrition-6/how-corals-feed

An excerpt from the article:

Energy and building blocks

The photosynthates which zooxanthellae provide their hosts with can deliver up to 100% of the daily required energy budget for corals1,2,3. These are often deficient in nitrogen and phosphorus, and are thought to be mainly used as fuel for respiration and mucus secretion, rather than being assimilated into biomass1,5. Zooxanthellae transfer glucose, glycerol, fatty acids, triglycerids and even amino acids to their hosts; these compounds are quickly metabolized or built into coral tissue. A part of the energy gained from photosynthesis is also utilized to continuously translocate calcium- and bicarbonate ions to the calicoblastic layer, thereby creating a skeleton (see the coral science archive for more information). The skeleton mainly serves as a refuge to hide from potential predators, and as a means to attach the coral onto a substrate. Unfortunately, photosynthates alone are not sufficient to build animal tissue2,4-9. These elements are ingested by corals by removing particulate organic matter (plankton, detritus) from the water, and by absorbing dissolved molecules. Heterotrophy is essential for all corals and can meet up to 100% of the daily required energy in corals which are bleached or inhabit deep or turbid waters1,12-18.

 

[Wolverine]

I don't think anyone is saying DSB's are inherently dangerous, rather, that they CAN be, given other factors.

I have not heard or read anything that would lead me to believe that his extensive research has been proven wrong, or that he no longer subscribes to the use of a DSB.

I don't know where he stands now, but several years ago Ron did say, many times, that he felt DSBs are inherently dangerous, describing them as "ticking time bombs" for any aquarium that used them. I fall into the category of people who think they can be a problem if not done properly, but are not in and of themselves a problem.

 

[gbru316]

I don't know where he stands now, but several years ago Ron did say, many times, that he felt DSBs are inherently dangerous, describing them as "ticking time bombs" for any aquarium that used them. I fall into the category of people who think they can be a problem if not done properly, but are not in and of themselves a problem.

I vaguely remember this as well, but as I was unable to find proof, didn't want to add it to the discussion.

 

[Wolverine]

I vaguely remember this as well, but as I was unable to find proof, didn't want to add it to the discussion.

It looks like it was a relatively short phase after one of his tanks crashed.

I remember it well because he tried to convince me to take mine out (it was about 4 years old at the time), after it had been his work that convinced me to do one in the first place. I don't have one in my current tanks, since they're nano tanks.