Plenums and the wasting "option"

[barryhc]

Kris, I can spell it out for you exactly, and I have already done so for half of the math. I'm trying to be ready to give you the other half. I'm trying to have "you" ready. Get it?

We're "crossing each other" too, as well. Each post is one place out of prooper position, because niether of us can type at the "speed of light".

I hope that was faster, nowl let's try again.

Thanks, > barryhc

 

[kbmdale]

You absolutely have to consider the "recovery rate", of the bacteria in this experiment, and tie that to the particle size, the depth of substrate, any layering that is going to be utilized, and then, of course, the Volume( "draw depth" ) and Frequency of the "draw".

I 100% agree. Remember this has to be done without changing the anaerobic and aerobic relationship of the zones in the bed. This will be the dictating factor in "flow" of and the amount wasted. If this is correct then I understand.


Mr. Hawke claimed it was the greatest thing since sliced bread, and then gave up on it after 9 mos. or so. That is not going to happen to me.

Don't get me wrong, I started this thread, but "magic bullets" do not exist, and "plenum wasting" will not be one either.

by taking it one step at a time we should be able to accomplish what was set out to be done.

I tend to like to find a starting point and experiment The math could be correct, but we have to account for the thickness of the substrate and the flow it will allow. My experiment should give some encite to those 2 variables. Agreed?

 

[barryhc]

Yes exactly, Kris. we are still passing in the night here, based on typing speed. As I have already stated, I can just about spell that ou for you, and this portion of it "should not be relegated to a consideration of particle size or bed depth, UNLESS, you want to waste by gravity.

I'm not recommending this, and I have reasons.

How close have we gotten to that 25 pages anyway.

> barryhc I just heard the "dinger", I think I'm going to die laughing!

 

[kbmdale]

anyone esle got any input fel free.

Barry, I got to get off for the night. Got some stuff I need to get done for work..arrggg...lol

later

 

[barryhc]

No Kris, I don't like that method or the experiment. Here is why.

You will not know anyhting meaningful from a "draw test" unless you draw through th "Plenum or waster" that you have built.

Especially if it is "gravity flow". We are going to have a "draw duration" that will probably be between 5 and 15 seconds, based on "bacreria recivery rates".

It needs to have "high flow", which may be beyond what gravity can deliver. Plus, how are going to control "draws" that occur for as little as 5 seconds possibly?

See what the consideration is here? > barryhc

 

["Umm fish?"]

Can I get in on this, too? I've been in conversation with Stu since the weekend about following this sort of idea. I have some questions for you all, though.

1. Is anyone concerned that what we are setting up here might turn into the nightmare we are trying to avoid? That is, we have, in essence, plenums of a sort (still, stagnant water in the pipes) with very small diffusion point. On the other hand, the water in the pipes will be taking trips periodically away from the sand beds, so the point may be moot.

2. Since the problem we are talking about (organics leeching from a DSB) is a problem that shows up, if at all, at roughly 4-5 years into the DSBs lifespan, how often does a sandbed need to be drained, really? Would it be better to do a fairly thorough bed drain very occassionally and allow the tank a mini-cycle? I know the point is to make this as easy on the life in the tank as possible, but I'm still trying to wrap my head around the time span necessary.

Thanks and thanks for this thread.

Andy

 

[barryhc]

I 100% agree. Remember this has to be done without changing the anaerobic and aerobic relationship of the zones in the bed. This will be the dictating factor in "flow" of and the amount wasted. If this is correct then I understand.

No, I really do not think so. You absolutely must carefully read this thread from the beginning, or we will definitely become lost. I think we may be already.

The existing conditions in a "sand bed" are the subject of very much debate, and controversy, but not enough consideration. I am not at all convinced that we "should be" replicating a "sandbed" and then putting a "plenum" underneath it.

I have stated to the contrary ( for the most part ) since the beginning of this thread.

That is just too easy, Kris, and it won't work. I can explain why, if you wish. You will have a serious channeling problem!

We can achieve something here, let's do so. you absolutely must read this thread carefully, or my responses simply won't answer your questions.

Let's try again tommorow. Yhanks > barryhc

 

[barryhc]

Yes you can.

"Umm, fish?":

1. Is anyone concerned that what we are setting up here might turn into the nightmare we are trying to avoid? That is, we have, in essence, plenums of a sort (still, stagnant water in the pipes) with very small diffusion point.

No. You need to explain about this "very small diffusion point". I don't understand your meaning here, but I doubt it.

2. Since the problem we are talking about (organics leeching from a DSB) is a problem that shows up, if at all, at roughly 4-5 years into the DSBs lifespan, how often does a sandbed need to be drained, really? Would it be better to do a fairly thorough bed drain very occassionally and allow the tank a mini-cycle? I know the point is to make this as easy on the life in the tank as possible, but I'm still trying to wrap my head around the time span necessary.

Very often, if you want it to do something other than what a sand bed does. I have stated since the beginning, and I will continue to do so, that this "Plenum Wasting" of a substrate is not a DSB, and it is not a PLenum, by any existing standards.

Now, go back to the beginning, like I have been explaining to Kbmdale, and READ IT ALL!

I have already covered at least the next 50 questions that are going to be asked. Go read the answers, they are already there.

Thanks for joining the thread, read it. > barryhc

 

["Umm fish?"]

No. You need to explain about this "very small diffusion point". I don't understand your meaning here, but I doubt it.

Very small diffusion point = the size of the holes in the PVC. As opposed to the open diffusion between plenum and sand bed with a normal plenum setup.

I have read the thread and I'm very excited about it. This thread, however, does not start from the beginning. There is, in your head, a defense of the idea. Unfortunately, I do not have this in my head yet and that is why I have questions about fundamentals. And, unfortunately, I'm pretty whacked on cold medicine at the moment. I'll try again in the morning.

Thanks.

 

["Umm fish?"]

I just read through the phosphate wasting thread you mention. It's all very interesting info. I have a quick (and probably silly) question: DSB are very efficient at taking us through the nitrogen cycle, but can't do anything about phosphate removal. Fine. Accept the limitations of the filter along with its successes. Now, we need to get P out of the system and you are talking about culturing and harvesting the phosphate locked inside bacteria before the system becomes overloaded and the P is leached into the water column. (Or, at least getting it into the water column so a skimmer can do the harvesting.)

Fine, but isn't there already an effective means of P binding and removal from our systems? Isn't that the point of macroalgae 'fuges (binding the P into the body of the plant and removing it from the system by harvesting)? Why is it necessary to move to micro-harvesting?

Thanks. And I hope the fundamental questions aren't too much of a distraction.

 

[CaptiveReef]

Plenums

Plenums

Hello everybody,

It's a great concept, but with the manifold design it would have to be the slowest flow possible, for example 60-90 drops a minute of water mass flows through a Nitrate tower. Any faster and you bring in oxygen which upsets the bacteria that handle Nitrate breakdown.
This would be regular flow as well as reverse. Diffusion works so slow, this duration process controls the amount of new water that is introduced to the Plenum/DSB.
A DSB will not remove Phosphates, The only natural source I have found is macro algae, you get rapid growth when there is Phosphates in the system, also you have to give the macro algae a night phase just as in nature.
These conditions allow for rapid growth of the macro's which in turn the rapid growth increases the plant's need for Phosphate.
At this point any Phosphate is ripped out of the water and the consumption rate exceeds the production rate, now at this point any Phosphate production is taken care of.
You now can do monthly pruning of the macro's to allow the lower layers of algae to get light and continue the rapid growth.
To be honest I do not vacuum any waste out of my system, or my vats, The micro fauna in the sandbed and amphripods just use everything.
Also when waste is allowed to break down, it is converted to it's final form which is amino acids.
Now when we talk about our systems the waste amounts are not huge, due to the fact we are using skimmers, carbon, macro, water changes, the left over waste levels are small and is used by the micro fauna.
I just tested my system for Phosphate, and it was 0. And that's with the practices I follow.
Plant life is the best natural Phos binder as well as using Phos-Ban.


CaptiveReef

 

[barryhc]

"Umm, fish?":

Very small diffusion point = the size of the holes in the PVC. As opposed to the open diffusion between plenum and sand bed with a normal plenum setup.

I really don't quite understand what you're saying here, about "diffusion" at the holes in the PVC.

Normal "plenums do not use "sand", they use 2-4mm gravel primarily, according to "Goemans and Gamble".

"Umm, fish?":

I have read the thread and I'm very excited about it. This thread, however, does not start from the beginning. There is, in your head, a defense of the idea. Unfortunately, I do not have this in my head yet and that is why I have questions about fundamentals. And, unfortunately, I'm pretty whacked on cold medicine at the moment. I'll try again in the morning.

Where is the beginning? What idea do you think that I am defending?

I am trying to discuss the fundamentals, but not the fundamentals of "conventional Plenums". I believe that one version of "plenum wasting", which is currently my favorite, is the High Frequency type, that simulates to a degree, "continuous wasting".

True "continuous" wasting is highly problematic in terms of "flow balancing", and I think that makes any "continuous" system just about impossible to make function correctly.

Thanks for your input. > barryhc

 

[CaptiveReef]

continuous wasting

continuous wasting

barryhc,

With this continuous waste theory, it's being broken down at a rapid rate that is why there is a buildup of Phosphate.
If I'm reading this correctly you are trying to design a system that will diffuse and allow for waste to be washed away, to be removed with a DSB/ Plenum application.
The only design I can think of allowing this to work would have to be installing an uplift tube in the Plenum through it to the bottom connect it to the manifold, then using a quick draw to quickly remove waste buildup from underneath the Plenum. The same would go with the manifold installed in the DSB. Both would have to be a quick draw, then stop otherwise oxygenated water would be drawn into both style beds.
It could work, with the DSB I suggest putting a layer of screen covered egg crate on top of the 1st 3 inches of sand that has the manifold buried in it, then place the rest of the sand on top of this screened egg crate. The waste that will diffuse into the area of the egg crate will be drawn faster than having to be pulled through a solid depth of sand.
Also at the hole points of the manifold is where you are going to get the greatest build up of waste, these draw points may need a reverse flush from time to time to loosen packed waste.

CaptiveReef

 

[barryhc]

There simply are no fundamentals for "Plenum Wasting", we are trying to develop them here.

There is no system to defend. I have not started the "wasting process" in my installed plenum yet. I don't have any data for plenum wasting yet, and I don't yet know of anyone who has.

In the mean time, it is my current point of view, that "drawing" water from the plenum, will affect the bacteria colonies in the "substrate above it for better or worse, so we need to make it for the better.

That takes a bit of consideration, and I have considered it a lot. I am going to consider it a lot more too.

CaptiveReef:

This would be regular flow as well as reverse. Diffusion works so slow, this duration process controls the amount of new water that is introduced to the Plenum/DSB

Watch about calling this a "Plenum/DSB". Some people may want to try that, and I'm all for it, if it can be made to work. I highly prefer to call the "stuff" above the plenum, "substrate".

2-4mm gravel( standard plenums ), is not sand, and the gradation of the substrate will need to be conducive to accomodating several factors.

The use of typical "sand bed" particles could cause a good bit of channeling difficulty at some 4-6" depth, and would certianly require some grade layering in order to avoid problematic "particle migration".

Plenum Wasting is not a "magic bullet" and other systems are necessary to compliment any well kept reef. Good flow is also of paramount importance, the list goes on . . .

Thanks, > barryhc

 

[kbmdale]

The eggcrate incorperated might need to be looked at. If I understand what you are getting at captivereefing, you are saying that the space the eggcrate will create may be enough to reduce the risk of o2 getting into the anaerobic zones we want to keep in the lower layers of the "Substarte"

Have you tried this? Very interesting. any reading on that?

 

[barryhc]

Now were getting there Captivereef. Our replies are passing each other here, causing mine at least to look a bit "odd".

I agree generally with your post including the egg crate, and I will respond later, it sounds pretty good.

Now if I just got this one out fast enoufh . . .

Thanks again. > barryhc

 

["Umm fish?"]

Thank you. The discussion of fundamentals on the 2nd page has helped sort things out in my mind.

The general definition of "plenum" in my head is "a layer of still water under substrate." While what you are discussing here is nowhere close to a classic plenum implementation, the water inside the PVC is still (when you are not flushing) and so fits my vague definition above. But, you intend to flush very often, so the point I was trying to make is moot.

In the implementation I intend to make, I will be using the manifold more as a DSB drain (with infrequent drainings), so I think I need to worry about the still water inside the pipes more.

Anyway, thanks again and I will be fascinated to see what results you come up with. And, if you convince me on the efficacy of frequent flushings, I will certainly give that a try, too.

Andy

 

[barryhc]

By CaptiveReef:

With this continuous waste theory, it's being broken down at a rapid rate that is why there is a buildup of Phosphate.

If we move the "entire water column" down, from the top of the water, to the glass at the bottom of the tank, and the distance we move this water is, say, 1/8", and that is 1 pint of water, and it takes about 5 seconds, and then we leave it alone for 8 hours, what is the effect going to be on the bacteria?

I have to start here. > barryhc

 

[kbmdale]

If we move the "entire water column" down, from the top of the water, to the glass at the bottom of the tank, and the distance we move this water is, say, 1/8", and that is 1 pint of water, and it takes about 5 seconds, and then we leave it alone for 8 hours, what is the effect going to be on the bacteria?

I have to start here. > barryhc

That is the Question that alot of other questions I have hinge upon. HOw do you figure that one out? I know a great chemist that could probably help but last time I asked him anything my brain hurt for 3 days after the answer he gave me....lol

 

[barryhc]

by CaptiveReef:

If I'm reading this correctly you are trying to design a system that will diffuse and allow for waste to be washed away, to be removed with a DSB/ Plenum application.

Well yeah, pretty much. I think though, that it is "fairly likely" that most bacteral activity in a "traditional sand bed" occurs rather close to "the top". Maybe something like the first 1" of depth or so, for "most" of the activity. This would be of course, unless that is modified with the addition of cukes, stars, and various other critters, and we can take that into account as well if you like.

Below that however, I think that the processes that are going on are less important to "real-time" water quality in a DSB, and may very well represent a good portion of the "sink", that is often referred to. "The deeper this is, the longer it lasts" syndrome, so to speak. I'm not certian about this, it is just speculation on my part.

I'm not bashing DSB's here, I don't do that, and I don't have any "side" to be on.

"If", anything is collecting in the lower parts of any substrate in a reef, we might want to "get rid" of some of it. If we start wasting water, and whatever is in it, we need to do so in such a fashion that is of benefit to the bacteria that are above this wasting.

"Occasional wasting" concerns me regarding what happens to these bacteria populations, if we draw water down by say an inch or more at once.

Ok, I'm getting off subject a bit here.

by CaptiveReef:

The only design I can think of allowing this to work would have to be installing an uplift tube in the Plenum through it to the bottom connect it to the manifold, then using a quick draw to quickly remove waste buildup from underneath the Plenum. The same would go with the manifold installed in the DSB. Both would have to be a quick draw, then stop otherwise oxygenated water would be drawn into both style beds.
It could work, with the DSB I suggest putting a layer of screen covered egg crate on top of the 1st 3 inches of sand that has the manifold buried in it, then place the rest of the sand on top of this screened egg crate. The waste that will diffuse into the area of the egg crate will be drawn faster than having to be pulled through a solid depth of sand.

Well, I think I see where you're going here. This a long way away from where I'm currently at, but let's go with it anyway, for now.

I agree 100% with the "quick draw". The reason for the short duration is to have a "shallow draw depth", in order to avoid "unduly" disrupting the bacterial activity.

After that, however, I'm getting lost here, as to what the advantage is going to be from "drawing " from the middle of the substrate depth. I see how it evens the flow for you, and avoids some portion of the potential channeling problem, but, I just don't understand how you get bacteria down to the bottom of the bed, if you are "pulling from the middle".

I suppose, that you could "draw" even amounts of water with even frequencies of wasting, but now you are drawing both "up from the bottom", and "down from the top" at the same time, with the manifold in the "middle". That's pretty wild, and I thought my approach was admitedly a "bit messy". :lol:

I agree wholeheartedly about the "occasional reverse flush", RIGHT ON!

Thanks again > barryhc