Revival of RUGF including NNR ! !

[wave98]

What is the lower limit for the grade of gravel for RFUGF? 5mm? Smaller? If you go too low I think that flow channels will quickly form and "short-circuit" the bed

Actually, I think that "short circuiting", or "channeling" is probably the best way to reliably create the Hypoxic zones that we are looking for. These areas or layers of oxygen gradation need not be vertical. They work just fine sideways or any other direction. :idea:

If you have "higher" flow in one area, it will be Oxic. if you no flow to the side of it, you have anoxic conditions. If you have Oxic and Anoxic conditions, you must have Hypoxic in between.

This could be done on purpose in an orderly fashion to maximize the Hypoxic areas, using different grain sizes of substrate. No more "sand". "Sand" doesn't mean anything.

> Barry

 

[Boomer]

piercho

There are many ways to do this to include using hot water bed stips taped to the bottom of the glass.

Most flexible insulators in the hobby IME don't last too

Yes and no it depends on who's you buy. German cables are DIN approved and last a life time but are very pricy, such as Thermik Omega Undergravel Heating Cable by Dupla. As I mentioned earlier if convection is to high the water bed just gets all oxic. Getting it hypoxic can be tricky, so sand would be a better choice than gravel, as it has less flow-throughput

http://www.shopsolution.nl/shop/home.asp?shopid=seameuk&deptid=dupla

lifeo

Just as something to stir things up, Mojo told me that he personally thinks NNR is a bad idea. Bob Fenner also told me that NNR was a bad idea for any tank

You better explain that or you are in trouble as NNR is denitrification, i.e., LR is NNR a SB is NNR. I take it you mean the Jaubert/Plenum System and/or the other "Bob" ? I also do not like plemums, to much to go wrong.

Paul go to link;

http://www.aquaristikshop.com/cgi-bin/neu/webshop.pl?userid=Mh8GEtQvPoof0hoOBMjsG1F8SSpPmDdphBo&t=e_3540

Look at the left side and parts #730675 & 7306070 and on the right part # 730650. 730650 can move up and down on. This moves part 730670 up and down and making part # 730675 go more or less into the tube 730650. Part 730670 is a overflow cap. So the higher 730670 and 730650 are up out of the tank the less fllow there is over the overflow and the more flow there is to the plates. The overflow should just be a small trickle to produce minimum pressure on the plates creating a more constant flow throguh the entire RUGF.

There was a guy why mailed me to say he used sand with an undergravel and the entire bottom would rise until the water found a weak place to push through. Not a very efficient way to go. And ofcourse that is because as you say, the sand is too restrictive

Then that guy has to much water pressure under the plate

Detritus will accumulate no matter what you do, it starts off as microscope pieces some of which is dead bacteria and it builds in size like lint does. There is very little space between sand grains and it would clog very fast.

I agree 100% and even if on used a diatom filter, even caked with a second layer of PAC, making it submicronic, it will still clog in time and produce excessive channeling and large sections will turn anoxic. Look at it this way, even if the grains were perfectly round and the bed thickness was the same through out, you will still end up with channeling you can not stop it, long term.


The whole issue with any UG system and I do not care what the grain size is, is that you can not stop channeling. The Eheim is/was the best attemp at it. Any time water moves through a media there is channeling. Even TF, as open as they are, have channeling. You can not control population dynamics or organic build up in a media that stops channeling, unless there is maasive wate flow and I mean massive.

There are some very nasty books that get into the flow of water through media, they would put you in Lah-Lah land I have both of them.

Porous Media: Fluid Transport and Pore Stucture

Dynamics of Fluids in Porous Media





Barry

Yah, a screen would stop that but I do not like the idea of a screen, just more to go wrong and cause more channeling. You have no real control on what it is going to be oxic, anoxic or hypoxic. It is all a guessing game At least with cables you have a better chance that is more controlling, long run. And I know of no one that has tried cables in a reef sand bed

Is there information available from other sources ? I have had a hard time finding any.

You will find some in Ron's article on SB. Have you read it His big link with all the refs. seems to be dead.

There is a book on the subject, more or less, which I have.

Introduction to the Study of the Meiofauna

http://www.reefkeeping.com/issues/2003-06/rs/feature/index.php

 

[wave98]

As I mentioned earlier if convection is to high the water bed just gets all oxic.

Exactly

Getting it hypoxic can be tricky, so sand would be a better choice than gravel, as it has less flow-throughput

Sand is better ?

The whole issue with any UG system and I do not care what the grain size is, is that you can not stop channeling. The Eheim is/was the best attemp at it. Any time water moves through a media there is channeling.

You failed to understand my last post Boomer.

There are some very nasty books that get into the flow of water through media, they would put you in Lah-Lah land

I think not.

Yah, a screen would stop that but I do not like the idea of a screen, just more to go wrong and cause more channeling.

How so Boomer, with 1/4" openings ?

You have no real control on what it is going to be oxic, anoxic or hypoxic. It is all a guessing game

I can control it.

I have read the majority of Ron's stuff. Much of it is very good. Much of it is "fuzzy". I don't care for Shimek's work as a source.

Reread post #41

and Thanks, > Barry

 

[Paul B]

I can only go by my 35 year old RUGF system, I don't think there are very many old systems out there with this system. Of course I also don't know if there is channeling in my gravel bed because this can not be seen. I think my bed gets fairly much the same volume throughout because I stir it up once in a while and when I add some salt or fresh water through the UG filter compartment as I do sometimes do I can see nice waves of differing salinities all over the substrate. Of course on a gravel to gravel basis I can't see what is happening but I think with gravel there is no problem. I am sure with sand there will be channeling that I do not want. Sand will clog, no doubt about it and I don't want completely anoxic zones anywhere. If I did I would not use a RUGF. IMO, small gravel is the way to go with this system. The detritus will take care of some "slight" clogging, but I think you will get a fairly even flow throughout the substrait. I agree with Boomer a screen is not necessary and it will cause problems. You can not remove it and you can not maintain the sand or gravel under it. A critter screen is not needed with this system. It will not hurt anything if anything burrows. My gravel is full of worms and brittle stars all the way under the plates. My nitrate is zero, there is almost no maintenance. I see no reason to run sand with this system unless for experimentation.
Paul

 

[ethanriley]

So reading back through there may be some merit to combining DSB and RFUGF? There my be some further merit to using heating coils in a similar method to that employeed in planted tanks. I throw molybedum back in again for supplementation purposes as there is some evidence to support that molybedum acts as a catylyst in conversion of nitrogenous compounds and avoids the production of hydrogen sulphide. By no means am I a chemist, but I throw my theory in to the rest of the mix

 

[piercho]

Paul,
that what I remember seeing in the early 80's for SW fish tanks before the wet/dry became popular, sand RUGF with little spots where it was obvious that the water was channeling up.

Boomer,
I work with the sub fleet, there is submerged elec eqt made for far worse abuse than a SW fish tank that will last a lifetime. I guess I don't need to tell an EOD guy that. But, at this time, I haven't encountered a piece of hobby electrical eqt I'd endorse for more than a couple of years use submerged. I haven't used any of the the german-made stuff but I have noticed some of that eqt is a far better design for use submerged (low voltage and/or grounded) than what is available stateside. But I do thank you for the link as I'm always interested in hobby stuff and sources for stuff that are better-made than what I've experienced.

Last thing. I've sent Dr Shimek a few odd invertebrates in the mail over the years and he has identified them for me. For those favors I'm prone not to bash him. Hes a pretty good guy with something of an ego problem, maybe. That description could apply to about 75% of people in the hobby, and 99.9% of those people CANT do me the service of weird invert IDs. So my vote is Ron's OK, you just have to be able to descriminate where fact ends and his opinion begins. Thats true for any "expert".

 

[salty joe]

It strikes me that a RUGF is a type of plenum.

Paul, if I understand correctly, your RUGF is fed by gravity. How deep is your gravel? I don't know if this could ever work with a DSB, but maybe if a taller colum of water is used to feed the RUGF.

I mainly posted to get subscribed to this thread.

Thanks all, very interesting.

Joe

 

[Paul B]

Joe. MY RUGF is fed by gravity. Water is pumped to a container about 6" above the water surface and it decends by gravity.
My gravel is about between 2 and 3" deep.
Paul

 

[wave98]

Paul, your "gravel" would be 2 to 5mm in dia. ( most likely ) when you put it in. Dolomite if I remember correctly. This material, if used exclusively, in a freshly set up tank would not work. At the stated "low flow" of 150 gph in your 100 gal. tank, the gravel would be highly oxygenated, ALL OF IT !

The vertical flow rate at those parameters is 9/16" per minute. That flow will highly oxygenate the water in the substrate and not allow faculative bacteria to process Nitrate. You have a goodly amount of sand and even "mud" in your gravel, as you have stated, and I think the substrate would not "denitrify" without it.

"Blockages" from the sand, and the mud, and the rocks, and the bottles and chain, and whatever else, are causing channeling in your substrate IMO. Without this channeling from the various blockages, there would not be any Hypoxic areas in the bed, and Nitrate processing would be little to none.

You also have ozonated skimming which is quite a bit of help, and your algae is also sucking up a good bit of Nitrate and P as well. I'm sure you would agree on these two.

I know you think that you don't have much channeling, and I just can't agree there. The sand and mud in your tank, along with mineral detritus from over the years, is surely mixed into your gravel, and having much the same effect as the "fine substrate" that I propose. In fact it is probably much finer, since I insist the substrate is properly sifted or graded to avoid "fines".

I DO NOT PROPOSE SAND ! SAND is too "non-descript", as we have been through already. I told you all that grain size would be a bit more "sticky" to define. Surely enough "sand" and grain size have become the "sticky points" of this proposed methodology.

I will state this again, I think that "short circuiting", or "channeling" is probably the best way to reliably create the Hypoxic zones that we are looking for.

This channeling can be created using different grain sizes in either mound shaped or vertical "channels" of larger grains to promote flow, and smaller grain sizes in between these "channels" to reduce flow, leaving Hypoxic zones in between.

Silica sand would be preferred here for most of the bed, not including the upper layer, in order to remain stable, by not dissolving and to resist clumping.
Still, thorough straining is required to eliminate "fines". I'm not sure just what grades of grain size are available in Silica, or Quartz.

What appears to be a better solution currently, is the option of using industrial glass beads made primarily from silica or soda lime. These beads are for all intents and purposes, Inert, they are glass. The beads are available in very tight grain size ranges compared to "sand", and do not have any "fines" at all. None, nada.

This is what will allow a RUGF, and sand bed to be set-up and become a denitrifying bed in a short ( similar to DSB ) period of time. Paul's tank took many years to become appropriate for Reef animals thru the addition of everything under the sun, and that is not such a repeatable methodology, even though it continues to work very well for him.

The best grain size for the denitrification areas in the bed is still the paramater that I haven't quite zeroed in on exactly. My guess is that .3 to .6mm ( .012 to .024" ) would work very well. Some might want to include some smaller grains for the bacteria, but I'm not convinced yet. This is about 7 times larger than the "fines" that are included as optimum, by Ron Shimek, for "sand".

I need a source of information on this that is not induced by Shimek. You got any other leads Boomer ?

Stating that it won't work is just closed mindedness, come on people, it will work if you want it to and do the work to design it properly. I am doing that, and IT WILL WORK. The most interesting comment thus far has been from LiveforPhysics, regarding the relationship between Nitrate and P. I have to think on that some more to be sure.

With puposely made "channels" throughout the bed, the flow could be increased a lot if you wanted to, and the Hypoxic zones would still be there, albeit a little bit smaller.

The top 2" should still be what the animals like most, and pleasing to the eye. I guess something between .5 to 1.5mm, or 1 to 2mm Araganite is probably the best choice there.

What I'm proposing here has not been tried before to the best of my knowledge, and has not been disproven to say the least.

> Barry

 

[Paul B]

Barry, I agree with just about everything you said. I am sure my 40 year old dolomite has broken down into much smaller pieces and there has been additions of some mud, sand, glass etc, along with countless urchin and snail shells, fish bones whatever. It is true my reef conditions can not be duplicated overnight. The first thing I tell people about RUGFs is that it will take months or maybe a year before it starts to process nitrate. I believe it will in time though due to the ever present detritus that you would be pushing through the gravel with this system. Even in a perfect system with the proper gravel (glass bead) size it would still take months to a year. Anerobic bacteria are not the fastest reproducers with aerobic bacteria present. I have heard of the glass beads but have no experience with them.
I am not sure of your numbers of the flow through my gravel. You may be correct. The tank is 72" long by 18" wide.
I also stress to prospective UG users to also use live rock as this system will not be able to utilize all the nitrate. It is a suppliment to other nitrofication means. I believe that the main benefit of the system is not for denitrification as there are other systems preferable to it but to the longivity and stability of the system with little maintenance. I don't think anyone can argue with me on that. Also there is very little chance of a system crash. The only way I can see that happening is if the gravel totally clogged and even though that would happen, with no maintenance eventually, it would be a gradual thing. I do stir the gravel a few times a year with a diatom filter but thats about it.
Paul

 

[wave98]

The first thing I tell people about RUGFs is that it will take months or maybe a year before it starts to process nitrate.

This is what I expect.

I believe it will in time though due to the ever present detritus that you would be pushing through the gravel with this system.

I think I could run enough filtration to eliminate ALL detritus from going through the RUGF, BUT I don't think I need to, or want to.

I am not sure of your numbers of the flow through my gravel. You may be correct. The tank is 72" long by 18" wide.

If this tank is 24" tall, it is a 120 gal.. Are you sure about the measurements, please check one more time.

If the tank is 72" X 18" then the inside dimensions are probably 71" X 17". which is 1207 sq. in. for flow to be dispersed through. In this case, the vertical flow rate would be .478", or 1/2" per minute. This will fully oxygenate anything that is flowing evenly ( without channeling ).

I believe that the main benefit of the system is not for denitrification as there are other systems preferable to it but to the longevity and stability of the system with little maintenance.

The longevity and stability are my first crireria for a substrate based reef tank ( any tank for that matter ).

Also there is very little chance of a system crash. The only way I can see that happening is if the gravel totally clogged and even though that would happen, with no maintenance eventually, it would be a gradual thing. I do stir the gravel a few times a year with a diatom filter but thats about it.

Again Paul, I couldn't agree more with the "crash avoidance", and the cloogging, should it occur would be a very gradual thing, if at all. I understand your concerns about sand, and I would not use it.

It takes some "stepping back" from it, to get a handle on what would happen
with much more carefully selected and utilized substrate.

There is no doubt Paul, that I have been inspired by your tank, and I had a preference for this before my "most recent" shot at reef keeping. It has taken a tremendous amount of research into substrates, bacteria, chemical processes, animals, "fauna", and on, et al, to come to this point, and now I need to do the experiment.

It will work. It will require various supportive systems, but it will be stable and reliable, and tend to avoid crashes, which is what we both want from it.

> Barry

 

[Paul B]

Barry, we seem to agree on everything. I hate when that happens :lol:
Now we can't argue about anything :badgrin:
My tank is 18" tall. I forgot what it was advertised as, I was a lot younger then, but I am quite sure it is 100 gallons.
As for experimenting, you have no Idea the amount of experimenting I have gone through and the quantity of inovation (and almost disaster) that this thing goes through. I have had flounders, lobsters, blue claw crabs, sea robins, mud, worms, home made ozonizers, filters, feeders, peristaltic pumps, gravity pumps, piston pumps, and don't get me started on lights. All of the rocks I either collected myself or built. (some of it is asphalt) I spend a lot of time trying to figure what I made and what I found and where I found it. I inject food with vitamins for certain animals and I inject live fish with vitamin A for frog fish, I even tried injecting anemones with Vitamin A. (I have a big bottle of it and needed a use for it)
I'm surprised anything at all is living.
You can get a look at the size of the dolomite here. Ignore the sea hare.
The second one, the moorish Idol eats from a dish with a tube going up to an auto feeder. All the food goes into the moorish Idol. None is lost.
(I'll give you experiments.) And some New York seaweed.
Have a great day.
Paul

 

[ethanriley]

Barry,

I went on a couple of sewer denitrification sites today to look mainly at the "sand" measurements they were using interestingly enough the measurements corresponded directly with what you had put forward earlier in the thread I believe two to three milimeters, but here was the interesting thing is that they were working with sand depths of up to 36" inches. To reduce "the channelling" they would "pump" defined as slow bursts of the recirculated water back through the media. this further ensured that faculative bacteria remained in a hypoxic environment and that the ultimate goal of nitrogen being released as a gas was achieved. I was wondering if as part of your "our" experiment if we set up a tank with a reverse flow UGF and a DSB comprised of a specific grain size wether or not we couldn't achieve the same thing the sewer guys were working to achieve. I was on the work computer if I can find it again in Google I will send it to you. It may ad merit to the further application. Paul how deep is your bed again?

 

[ethanriley]

http://www.freepatentsonline.com/6818123.html


Check this out! Hope I pasted it right

 

[Paul B]

Barry 2 or three inches, Maybe I will try 36"

 

[Boomer]

Barry


You got any other leads Boomer ?



There is tons of info on this subject but I have yet found, still looking for you, any info on sediment size for denitrit, that is "best".

There is lost here, to help you undestand;
http://www.ozestuaries.org/indicators/sediment_denit_efficiency.jsp

There is also the book the book I mentioned;
Introduction to the Study of the Meiofauna

which abounds with info but nothing on denitrif..

IMHO, based on data and articles, it makes not difference what the sediment size is, in research or in nature, just whether or not it is taking place. You only need a hypoxic zone. It should be obvious, that it can occur in any sediment size and maybe that is why it is not an issue in research papers or books. What you are trying to do is a little different, create a hypoxic zone, based on sediment size, in a reef tank.

Two of my books really get into the subject of bacterial biogeochemistry ( the actual title of one), with chapters just on sediments and denitrif. and neither even breaths the word sediment size. All of the articles I looked at do not either.

Somemore to add in new research ideas

Current HYPOXIA Program Questions (Harvey, Bohlke, Voytek):

Streamwater flows easily through the relatively coarse stream bottom sediments at Sugar Creek, Indiana (2-mm median grain size), delivering streamwater nitrate to sites of potential denitrification as deep as 10 - 15 cm in the streambed. Can evidence be found for denitrification throughout the entire depth of the hyporheic zone, and is this 'deeper' component of flow and reaction in this environment important for reducing downstream nitrogen loads? What is the relative importance of hydrologic (stream velocity, grain size, and hydraulic conductivity of bed sediment) and biogeochemical factors (nitrate concentration, carbon quantity and quality, and redox potential in bed sediment) that affect the rate of denitrification in the streambed?

I just found this

http://www.aoml.noaa.gov/general/lib/CREWS/Cleo/St.%20Croix/salt_river89.pdf

http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=12493214&dopt=Abstract

http://www.seas.ucla.edu/stenstro/o/c43

and I spaced this out

http://www.advancedaquarist.com/2005/7/aafeature

http://www.reefkeeping.com/issues/2004-11/eb/feature/index.php

 

[Paul B]

Quote

"The impact of filtration rates in the range of 0.15-0.38m/h, filter depth of 0.5-1.5m, and sand size 0.3-0.5mm on nitrogen removal processes at temperatures of 10-39 degrees C was assessed. Nitrification efficiency, denitrification efficiency, and total nitrogen removal efficiency correlated well with filtration rate and sand size only, with all three parameters inversely proportional to the square root of the aforementioned two process variables. Nitrification exhibited the most sensitivity to filtration rate and sand size. The filters produced effluent with turbidities of 0.1-0.5 NTU, SS concentrations of 3-6mg/l in the fine sand and 6-9mg/l in the coarse sand."

Boomer, this was from, I think, the second article you posted. Interesting but it would be difficult to adapt these measurements to a tank. But I guess it is the only data available.

Thanks for posting it Boomer.
I guess I will go and add another three feet of sand to my tank:lol:
Paul

 

[wave98]

Two of the links were particularly interesting.

"The impact of filtration rates in the range of 0.15-0.38m/h, filter depth of 0.5-1.5m, and sand size 0.3-0.5mm on nitrogen removal processes at temperatures of 10-39 degrees C was assessed. Nitrification efficiency, denitrification efficiency, and total nitrogen removal efficiency correlated well with filtration rate and sand size only, with all three parameters inversely proportional to the square root of the aforementioned two process variables. Nitrification exhibited the most sensitivity to filtration rate and sand size.

I would call that sensitvity to oxygen level, which I have found to be reported as .5 to 2.0 meq/L, to be considered the hypoxic level that promotes denitrification by Faculative bacteria. ( 1.0 meq/L nominal ) Any comments on this Boomer ?

Inches Per Minute = IPM

. . . . . . . . . . . . . . . . . GOVT . . . UCLA . . . Paul's . . . MY
. . . . . . . . . . . . . . . . . LINK . . . . LINK . . . TANK . . . EXP.

The vertical flow rate = .17 IPM. . 11.81 IPM .48 IPM . 2.4 IPM

. . . . The filter depth = 39" . . . . . 108" . . . . 2.5" . . . . 7"

The Grain size(in mm) =(.3-.5) . . . (.6) . . . . (3-5)* . . .(.3-.6)**

. . . . The Dwell Time = 3.8 hr . . . 9 min . . . . 5.2 min . . 2.9 min

The GOVT link describes a "slow filter". The UCLA link describes a fast filter. Both of these are "being fed" extra nutrition, especially the UCLA "fast filter" version, and this has a large effect on necessary "dwell time". Both of these are "fluidized filters" with no channeling, and other parameters that are different from Pauls tank and My Experiment. These "fluidized filters" are not very conducive to use "inside" of a "Reef Aquarium".

The dwell times from Paul's tank and My Experiment do not identify the effects of channeling, and therefore do not relate directly to the "linked studies".

1) (*) Paul's grain size is actually all over the place as previously mentioned, and works well because of it. This from the addition of mud, sand, etc.

2) (**) My grain size as listed conforms well with the two links, but this grain size is only for the denitrification area, and has 1" to 1 1/2" wide channels of 3-5mm gravel, spaced at approx. 4" intervals, to force channeling to occur predictably across the entire sand bed.

3) The "forced channeling" is what makes the system work. Paul's tank channels and works well by accident and through special maintanence, and works very well to be sure. My "experiment" is to cause this channeling very much "on purpose", and quite predictably, and controlably.

This is the "read" I get from the links, and a further explanation of the methodology that I am proposing.

From your picture there appears to be a whole lot of 1-2mm stuff in there, just under the larger "surface stuff".

Have at it ! > Barry

 

[Boomer]

Bary

I would call that sensitvity to oxygen level, which I have found to be reported as .5 to 2.0 meq/L, to be considered the hypoxic level that promotes denitrification by Faculative bacteria. ( 1.0 meq/L nominal ) Any comments on this Boomer ?

Two comments

1. meq / l. I take it that is a typo and you mean mg / l O2. O2 is not measured in meq, as it is not a charged ion but a molecule.

2. Something I left out, forgot, although I have brought it up here on other threads on denitrif.. O2 can be very misleading because denitrif can take place right on the surface of grains or even the glass . Many dentiro's can produce their own environmet that is hypoxic. The start out as oxic and then produce a thin outer mucus like layer that produces a hypoxic environment to allow them to go facultaive.

And yes Barry many systems work as you put it "by accident ". Some trickel sytems, which usually are know for producing nitrate, "by accident", can bring about denitrif.. and produce 0 or near 0 mg / l NO3-. As seen, even fluidized beds can do it. Heater cables would also probably produce "forced channeling"

 

[wave98]

My mistake ( obviously ) Boomer. Not paying enough attention on the mg/l thing, thanks ! How about the numerical values though ?

Yes, some bacteria CAN produce their own micro environment, in an otherwise aerobic area, which makes it an interesting side note, but this does not occur with a commonality, to compare with generally Hypoxic zones.

Fluidized beds are a much more calculated and predictable method than accidental, and the advantage of grain size differentials over heat tape is the VERY much higher flow that can be utilized while still maintaining proper Hypoxic conditions. The "grain channels" also offer a very much larger surface area of Hypoxic condition than any other method.

Thanks for the links Boomer, they were great !

> Barry