Plenums and the wasting "option"

[barryhc]

Nice post, voodoody, were in the same ball park here obviously. We are passing replies simeltaneously, which is becoming common in this thread. I'm still conisdering the info. in your "last" post. <I do not think significant nutrient loads are present.> I will be reading it more thoroughly "right now".

"We" will both get the opportunity to start "wasting" soon. Can you tell me more about your "substrate", and any layering at all. Also, what size tank, and what are your objectives "animal wise".

Other important "equipment" on your system?

Thanks again, very much! > barryhc

 

[voodoody]

Tank size is 190 gallons low iron glass + Redmond Reef refugium with chaeto + Euroreef protein skimmer (CS-8 series). I used the CaribSea Special Grade Reef Sand. Closed loop is a Sequence Dart with four outputs. Two outputs are Sea Swirls for turbulance. Two 250w metal halide DE (10k) and one 175w DE(20k). This will be mixed reef when fully stocked with soft and sps, clams and a few fish (species undecided at this point).

 

[barryhc]

We might have to revise the "diffusion" definition if anyone is interested. I have seen "diffusion" . . . "flashed around" like a "big gold ring" elsewhere. I am just here to learn, and understand.

By the way voodoody, LDRHawkes plenum design was "pretty close" to begin with ,as I see it. The "goemans" style screen and eggcrate looks better to me. ( sounds like what you're using ) "Feeder tube cramming" looks good as well.

I like to pull from the center of the manifold when possible, but it is not a prerequisite of course.

It sounds like your "draining by gravity", and I'm intersted in your "test flushes" there.

Thanks again! > barryhc

 

[barryhc]

See us "passing in the night" again? Magnificent set-up by the way, I haven't gotten that far yet. I'm still "playing with my "little hex" plus "fuge. I'm preparing here, for a 200 gal. probably for installation around christmas. your set-up sounds exceedingly similar to where I'm headed with the "big one".

Thanks again! > barryhc

 

[barryhc]

Saltyjoe, I would be a little more concerned with channeling, if I were you, but then I'm not. However, I particularly like your "U tube" idea.

I like the part about varying the "collection" portion of the "gizmo" to control "draw volume".

I still like "Short burst" "High flow" for avoiding channeling, but heh, I just can't help it, I guess.

In any case, I think your right on, about checking for phosphate, and whatever else you're interested in.

Welcome to the thread! > barryhc

 

[CaptiveReef]

By CaptiveReef:


>>CaptiveReefs' definition of diffusion was accepted as stated, and I still accept it.

Still, after the Anoxic bacteria strip the oxygen molocule from NO3, and then bubble up Nitrogen gas, what is left from that process, besides the bacteria? No dispute here, but do you have a link for this? I love to read.<bhc>

By CaptiveReef:


>>OK, I'm getting confused here, and I rarely get confused.

I thought we wanted to remove the Nitrate in the Anoxic zone, and so, if "we" add oxygen, we will "remove the Nitrate"?, and we are going to get a "Nitrate spike"?

Help!! where's that "reading" on this, now my head hurts too!

Thanks again, >"reading, links" > barryhc

Okay let me explain, the Nitrate laden water is pulled downward into the bed by gravity, diffusion,(Nitrogen bubbles up, for every bubble new Nitrate laden water takes it's place in the bed.
If we disrupt the entire bed by allowing new oxygenated water to enter from the top and make it all the way to the bottom , it will change the entire environment that the bacteria need to perform there job. There will be no stripping of oxygen from the NO3 molecule. The entire process/environment will be compromised, now that this has happened the bed's ability to diffuse Nitrate has been changed and Nitrate levels will start to increase,(spike) until the bed is able to return back to it's original state/ proper environment to support the bacteria.
Remember we have to keep the bed pretty much oxygen free so the bacteria will continue to use the NO3 for their oxygen source.
As soon as the bed receives additional oxygen this stripping of the NO3 molecule stops.
That is the reason for small controlled draws from the bottom of the bed,to remove waste, but not pull the water all the way down into the bed. IMO I would only allow the 1st inch of the upper bed to be allowed to receive any introduced oxygenated water.

CaptiveReef

 

[voodoody]

Egg crate will allow "short circuiting" according to ldrhawke. I think he is right. I modified his manifold. Mine consists of two "grids" with pvc running both vertically and horizontally rather than just horizontally. These are both connected to a center manifold. I took digital photos before it was covered with substrate, however, I am having a hard time locating.

The concept that flushing will remove nitrate and the bacteria will starve and therefore will not be able to convert newly formed nitrate and one will see a nitrate spike does not make sense in my humble opinion. Bacteria do not die off from a short term lack of nutrients. They will be able to process them as soon as they become available again.

 

[barryhc]

Voodoo and Captive both: I have an open mind entirely on the oxygenation issue. Actually, I'm more concerned than voodoody, and less concerned than CaptiveReef, so I'm just going to keep "following" on this. Thank you both!

By voodoody:

Egg crate will allow "short circuiting" according to ldrhawke. I think he is right.

>>This part I don't quite follow, but maybe.

"Short circuiting" in the plenum, based on "channeling", in the substrate above?

If so, this is my reason for the lower level "gravel" layer, up to 2"-3" deep, and then 6mm plastic screen "critter barrier". However, maybe I see your point. voodoody, could you elaborate? I'm listening very carefully. Thanks again > barryhc

 

[voodoody]

Exactly. Short circuiting based on chanelling. The flow will take the path of least resistance. The idea of numerous tiny holes rather than egg crate is to make it less likely that some zones that will receive no flow due to uneven clumping / consistency within the substrate. This had not occurred to me, but I do think that ldrhawke knew what he was talking about hear. A detailed discussion of this in the prior thread was quite convincing to me.

 

[barryhc]

Remember we have to keep the bed pretty much oxygen free so the bacteria will continue to use the NO3 for their oxygen source.
As soon as the bed receives additional oxygen this stripping of the NO3 molecule stops..

Maybe we're getting somewhere here, but the "upper portion" of the bed needs to remain Aerobic in order to produce the NO3 in the first place, Right? ( unless you're favoring bio-balls, which I'm not )

Then the Anoxic portion of "the bed" which is "under" this "Upper Aerobic portion, can perform the "work" that you describe. Am I still confused?

That is the reason for small controlled draws from the bottom of the bed,to remove waste, but not pull the water all the way down into the bed. IMO I would only allow the 1st inch of the upper bed to be allowed to receive any introduced oxygenated water.

Or less possibly, I don't know for sure about any magic number for Aerobic zone depth, I'm still looking for information, and I still believe that the zone depths will be other than published information if "simulated continuous flow" is performed on the substrate. > "oxygen gradation"

I'm still particularly interested in the Phosphate processing, that I seem to understand, is occuring in the "lower Ph" Anoxic and anaerobic portions of "the bed".

Any thoughts here?

Thanks again, this is progress. > barryhc

 

[voodoody]

Unlike ammonia which can ultimately be converted to gas which bubbles off, phospates can only be incorporated into the bacteria. Ultimately the DSB acts as a sink for phosphates, sulfur containing compounds and heavy metals. This is thought what acts to ultimately cause DSB's to crash. The sink gets full and starts to leak nutrients back into the water column. This is why I think a refugium is important. Harvesting macroalgae can actually eliminate or export this out of the water column.

 

[barryhc]

Exactly. Short circuiting based on chanelling. The flow will take the path of least resistance. The idea of numerous tiny holes rather than egg crate is to make it less likely that some zones that will receive no flow due to uneven clumping / consistency within the substrate. This had not occurred to me, but I do think that ldrhawke knew what he was talking about hear. A detailed discussion of this in the prior thread was quite convincing to me.

Where are these "numerous tiny holes", and then, why "rather"than" egg crate.

I have 72 .040" dia. in the "plenum manifold", and egg crate with screen over that, then the gravel over that avoids both "clumping" and "particle migration" as well, as I have
explained at some considerable length.

I have not even seen the previous link here. I saw the basic explanation that LDRHawke made, through a link about 5 mos. ago., which was one "post" including pictures. and nicely done.

I have asked LDRHawke directly, and specificly for his opinions, and he has not responded.

Thanks again > barryhc

 

[barryhc]

Unlike ammonia which can ultimately be converted to gas which bubbles off, phospates can only be incorporated into the bacteria. Ultimately the DSB acts as a sink for phosphates, sulfur containing compounds and heavy metals. This is thought what acts to ultimately cause DSB's to crash. The sink gets full and starts to leak nutrients back into the water column. This is why I think a refugium is important. Harvesting macroalgae can actually eliminate or export this out of the water column.

This is exactly how I understand it. I said the system I'm looking at installing is almost identical to yours.

I will build my own refugium, my own "lighting hood" and or whatever we want to call that, and possibly my own skimmer.

However, beyond that the only other difference between our systems, may be that I want to include Gobies, and possibly Jawfish, which you have not yet specified.

I may even include a "Gobies garden" portion of substrate management in 1/4 or less of the tanks "substrte area" as well, in order to avoid some portion of the "channeling problem" that "they" would tend to promote with their "burrowing Habits".

Wasting a plenum can "export" some of this Phosphate, sulfur, and metals "sink" can't it? Maybe even avoid a "crash"?

How are we doing? > barryhc

 

[barryhc]

Voodoody, can you give us some information on your "drain by gravity" test flushes, that you conducted shortly after installation? I'm particularly interested.

How are we doing on "refugiums" and "sink wasting"?

Thanks again, you are helping a lot, and it is appreciated!

> barryhc

 

[barryhc]

Wasting a plenum can "export" some of this Phosphate, sulfur, and metals "sink" can't it? Maybe even avoid a "crash"?

This is why I pursued "plenum wasting" in the first place, about 8 mos. ago.

"Plenum wasting" was actually "in Vogue" about 6 years ago actually, and "everyone" gave up on it, as far as I know.

LDRHawke decided to try it again, and was highly satisfied for "a time", and then he gave up on it too, as well. If that's not so, he is welcome to explain otherwise.

Where do we go from here?

Thanks to all! > barryhc

 

[barryhc]

So, is it the "substrate" that is the question here? Maybe how "it" affects the bacteria populations, "channeling", "Phosphate binding", "gill damage" for some "critters", any others?

I hope so, that is where I started this thread. I hope that "it" goes wherever else it needs to go, in order to achieve success!

There may be many other considerations as well. Let's "chew on them" some heh?

And let us all continue to enjoy the reef keeping hobby! > barryhc

 

[salty joe]

Main Entry: difÃ"šÃ‚·fuÃ"šÃ‚·sion
Pronunciation: dif-'yü-zh&n
Function: noun
1 : the process whereby particles of liquids, gases, or solids intermingle as the result of their spontaneous movement caused by thermal agitation and in dissolved substances move from a region of higher to one of lower concentration

This is what diffusion has always meant to me.

 

[barryhc]

That looks like a very good definition SaltyJoe, and it doesn't sound like the "Gold-Ring" type either. Thank you very much.

The one thing that I am not sure about is what kind of membrane should I use for the very bottom of the sand bed to keep the very fine sand out of the plenum?
Joe

Membrane?

Did you read about substrate, gravel, plenum, eggcrate, screen, "critter blocking" screen, PARTICLE MIGRATION, etc., earlier in this thread?

Let me know if it remains a question.

Thanks so much for contributing! > barryhc

 

[barryhc]

In case anybody new to the thread missed it.

Now that "we've made it to this point, I think that some "layering of the substrate is going to be quite valuable for various reasons.

No, we don't often find it in "the wild" that way. I keep my tank in my "Diver's Den", not . . .

We don't have "wasting plenums" in the wild do we?

Ok, I just couldn't help it, and I'm only referring to the "High Frequency" type of plenum here, that I have been promoting. There may end up being several types of successful "systems" that come out of this investigation, and I certainly hope that is the case!

Just the same, I'm referring in this particular "post" to layering of the substrate that might be conducive to the overall performance and longevity of a "High Frequency Wasting" type of plenum.

Ok, let's start with typical ( or standard ) type of plenum according to "Goemans", and start from there.

Let's try to pull from the center of the tank as much as possible ( details upon request ).

Let's also cram in as many feeder tubes as possible and use lots of rather small holes to "balance flow" across the substrate area.
Calculate these hole requirements to match the flow, don't guess please.

Put in the egg crate and screen just like the "Goemans" model. OOPS!!!! . . . WHOA THERE, HEH?

"Screen", is not very descriptive, and probably works fine in a "Goemans" style plenum, but this "might" deserve some consideration. I have screen on my plenum, and I'm not too worried about it. Mine has about 1.5mm ( or 1/16" ) holes in it.

Now here is where I may "throw" some people off, but I'll take it slow.

Let' start with the larger particles at the bottom, right on top of the screen. How about 3-5mm. That is not "sand", that is gravel. Let's use nicely grade stuff here and rinse it thorughly first .

Why, you ask, I'll get to that later. Let's just keep looking at this "model" for a few more steps here , Ok? Well, alright, I don't want anything to cause blockage around the plenum, you see.

1/2 " deep of this gravel should probably suffice from a "flow" standpoint. "But what about the anaerobic bacteria", you say, yeah, they'll be there, what about them?

Ok, how about, say, 1"depth of 2-4mm gravel above that? What's that for, you might ask? Well, . . . "Goemans" uses up to 4" depth of this stuff, so are you asking if it is too much, or too little?

The "hope" here is, that there is a lot of Anoxic activity in this "level" of the substrate. How thick is this Anoxic zone anyway, that everyone seems to know so much about? Remember the .5mm thickness of "Anoxic zone" mentioned previously in regard to DSB's?

All right, so here is where get to start "playing with it".

Now the 2-4 mm layer of gravel, is going to block "particle migration" down to about .3mm, that is three tenths of one mm. Don't think so, heh? Try me! Sorry, can't help it on occasion.

If you want to go with particles smaller than that, you may want to add, yet another layer of .7 to 1.7mm particles, say another 1/2" to 1", whatever.

Let's see now, were at 2" to 2 1/2" deep now right? ( from the "bottom up" )

Well, what do you want to do with it now? That is up to you of course, but for me . . .

Well I,m not going to be having "plugging issues" in the plenum now, because, I'm blocking "particle migration" with the afore-mentioned "larger gravel".

This seems a little bit counterintuitive, doesn't it? That is how I see it working.

Ok, for me, it is now a matter of what "critters", that I ( "we" )want to keep. H-m-m-m . . .

Let's put in a second screen here, to keep the "critters" from messing with our carefully controlled lower layers, heh? I'm thinking 6mm plastic mesh. I'm only trying to stop critters here, nothing else!

I like crabs, and snails, and pods, and cukes maybe, . . . micro stars maybe? Geeze, this is the part that is interesting here, because these animals could have some effect on the the "Oxygen Gradient" in the upper level of the substrate. right?

I think I might try some .7-1.7mm here, but I'm not so sure about how deep. The Gobies might like 3" of this, but that may not suit the "oxygen gradient" I'm looking for.

Oh well, more investigating to do!

What's next? > barryhc

Membranes, channeling, plenum clogging, substrate, depth, bacteria populations, critters, variable individual setups, U-h-h-h-h ?

What is next? > Thanks all. > barryhc

 

[barryhc]

Main Entry: difÃ"šÃ‚·fuÃ"šÃ‚·sion
Pronunciation: dif-'yü-zh&n
Function: noun
1 : the process whereby particles of liquids, gases, or solids intermingle as the result of their spontaneous movement caused by thermal agitation and in dissolved substances move from a region of higher to one of lower concentration

This is what diffusion has always meant to me.

I think it's the "dissolved substances move from a region of higher to one of lower concentration" part that is probably the most meaningful to "us" here as "reef-keepers".

I think too many people have been using "it" as a reference to "water flow" in general that has caused some misunderstandings.

Thanks again! > barryhc