Plenums and the wasting "option"

[barryhc]

Originally posted</a> by sradmin Thought I'd liven it up again with a couple of pictures:

Thanks for the pictures Steve, they are 4 1/2 stars at least!!!

All the information that you gave seems to be "right on", with everything that I have read on the animal.

It seems like we're turning into a "Jaw-Fish-Club" here!!!!!

I guess it turns out that most of us have VERY GOOD justification for insisting on the "deep substrate".

I think it would be good to have a Jaw Fish-Gobies "club thread", for relating our experiences and husbandry techniques for these fantastic animals.

This forces me to state again, for those who view the thread, and haven't read in it extensively, that, for me anyway, the PRIMARY, criteria here, is to have a relatively deep substrate for the animals that require it, with a sustainable substrate, that avoids "crashing", and that nutrient processing is a secondary function, that most of us are very interested in, and are working on refining a "model" to to achieve these goals.

I think I will start a "Jaw Fish-gobies" thread soon, to further the interest in these animals, and not "muddy the waters" here in "Plenum wasting".

PLEASE-PLEASE , don't get me wrong!!! I love the "sand creatures", and I am not bothered in the least that we have been posting "here" about them, but, if we go on too long about them we might lose some people who are interested in plenum wasting, and we could go a lot further with our "beloved critters" in the seperate thread as well.

So I guess, I'm actually saying that I hope "You Guys" follow to the new thread, and I will not be bothered in the least with anything about them that is posted here. In fact I will enjoy it extremely!!!!

I will start "The Jaw Fish and Gobies Club" thread and I will put it in advanced topics for now, and see if RC will allow it to remain there.

By the way, Steve, could you tell us if you are in the process of going bigger, or else wise considering implementing plenum wasting in one of your tanks. If so what size, what critters, etc.?

Thanks all, this is getting better everyday!!!! > barryhc

 

[salty joe]

Do you think polypropylene beads would be an acceptable substrate to surround the piping in the plenum? I have some friends in the plastics business, and I'm pretty sure that the beads come in a lot of different sizes.

Also, was it mentioned somewhere on this thread that the holes in the pipe would be a different size if they were surrounded by gravel?

 

["Umm fish?"]

Joe: I can't imagine why they wouldn't work. They are chemically inert and heavier than water, right?

I'm adding water(!), but running into issues. Better get back to it....

 

[barryhc]

Thanks Joe, interesting idea. I can't see where those beads would cause any problem. I'm not sure if they would help anything either. They don't buffer anything, and I don't think we care. They would have less surface area to harbor bacteria, and I don't know if their inert condition would resist bacterial colonization or not.

I suppose they would tend not to "bind" P, or "leach" it back later either. This would probably be quite similar to using quartz, siica, or other "nonbuffering" substrate.

I guess the question is do we want to encourage any of the above activities or not, and that kind of brings us back to the bacterial conditions, pH, etc.

They might resist bacterial growth, and obviosly would not "shed" or otherwise be affected by pH, and that might be a good thing.

It could mean that they would resist "floc" and glycolization, etc. and therefore assist in unencumbered exit of the small particles that will eventually make it through the "gravel membrane".

I have been thinking about moving away from aragonite already anyway, to avoid any potential P leaching, and more importantly, to use a substrate than won't "melt" over time in low pH conditions. This helps to further avoid clumping.

I have to do more investigation on that concept. Do we have any other considerations here?

oopS! Joe, the hole sizes will be the same if gravel ( or beads ) is used for a "membrane" or bottom layer, as opposed to the void space. The flow restriction in the be bed, will be dependent on the sand or substrate that is used above the gravel membrane. The gravel around the plumbing can still flow much more water than the plenum feeder holes, which may be a case for not getting too large with the bottom layer of gravel.

If the beads are used at the bottom, and can't "melt", then smaller gravel ( or beads ) here would be more reasonable, and would further improve on the avoidance of "channeling".

Thanks for keeping us rolling! > barryhc :beachbum:

 

[miatawnt2b]

What do you guys think of putting a layer of 1" polyester batting material over the manifold as a membrane? Laying sand on top should squish the material to about 1/8". I have been using this stuff for filter material in my emperor for years and it does not deteriorate. It has large surface area, and should keep finer sand from being sucked into the plenum. I wouldn't think this would cause channeling?

Thoughts?

-J

 

[barryhc]

<a href=showthread.php?s=&postid=6250252#post6250252 target=_blank>Originally posted</a> by miatawnt2b
What do you guys think of putting a layer of 1" polyester batting material over the manifold as a membrane? Laying sand on top should squish the material to about 1/8". I have been using this stuff for filter material in my emperor for years and it does not deteriorate. It has large surface area, and should keep finer sand from being sucked into the plenum. I wouldn't think this would cause channeling?

Thoughts?

-J

I'm thinking, . . . . . . . . well, let's see, . . . . . . .

"-J", I think your glasses are "fogging".

PLUG! - PLUG! - PLUG!!!!!!!!!!!!!!!!!!!!!!

If fine particles in the substrate are not allowed to flow through the plenum plumbing, AND EXIT THE SYSTEM, then these fine particles will accumulate at some point in the substrate where the restriction is highest, and plug the substrate at that point eventually.

The "Gravel Membrane" solves this problem.

Anything that restricts fine particles will . . . . . . . . . .

PLUG! - PLUG! - PLUG!!!!!!!!!!!!!!!!!!!!!!

The finer substrate in the layering model, only succeeds in avoiding this failure by way of the "fauna" that are allowed to keep it broken-up, and therefore keep any "fines" that get into the substrate, including that which comes from "boring creatures" in the live-rock, moving through the substrate, down thru the "gravel membrane", and into the plenum plumbing, to be "wasted" along with whatever else.

If you don't believe that "fauna" can maintain the finer sand, to avoid plugging, then you are only left with larger gravel as a solution to substrate clogging, and I think that leaves you with poor denitrification capabilities, unless you consider going 12-15" deep with your substrate. This sounds like a problem.

Use the "Gravel Membrane". I know it sounds like I'm "COCKSURE" here, and I am!!!!!!!!!


Fine membranes stop the movement ( or migration ) of small particles and then CLOG ! ! ! ! !

Thanks, barryhc :beachbum: :thumbsup:

 

[miatawnt2b]

So If i understand you then, when you waste your plenum, you are not worried about sucking some of the finer substrate through the plenum. I assume you just add a cup of sand every so often?
Thanks,
-J

 

[barryhc]

<a href=showthread.php?s=&postid=6262488#post6262488 target=_blank>Originally posted</a> by miatawnt2b
So If i understand you then, when you waste your plenum, you are not worried about sucking some of the finer substrate through the plenum.

No, I certianly am not.

miatawan2b, you REALLY NEED to read the last 3 pages in this thread very slowly and carefully. The answers you need are there in very finite detail.

Still, I will try to help you a bit with "particle migration". It seems to cause a lot of people some difficulty. Firstly I propose a "gravel membrane", which RESTRICTS particle migration of "fines" through layers of successively smaller grain sizes as you proceed "up" from the plenum.

The Gravel Membrane DOES NOT ELIMINATE the migration of particles. It restricts the migration of particles down to 16% ( or 1/6 ) of the size of the grain size of a particular "membrane layer". This means that particles larger than 1/6 of the "current layer grain size" WILL NOT PASS THRU. Particles smaller than this size WILL PASS THRU.

This 16% or 1/6 ratio holds true for ANY SIZE of particle, whether it be "mud", or bowling balls, the ratio remains the same.

Study the graphic below. Think about it for a few minutes.

Now the layering model: ( from the top surface )

layer #1 > 1-2mm ( 1.5mm nominal ) > .25mm particles cannot pass thru

layer #2 > .7-1.7mm ( 1.2mm nominal ) > .2mm particles cannot pass thru

Critter Screen with 6mm ( .240" or 1/4 ) openings > only effects "large critters"

layer #3 > .2-1.2mm ( .7mm nominal ) > .11mm particles cannot pass thru

.11mm particles, are considered to be "mud"!!!!!!!!!

A .11mm particle, is .004", or the diameter of one of your hairs.

NOTHING LARGER THAN THIS CAN GET THROUGH LAYER #3!!!!!!

ONLY PARTICLES SMALLER THAN .11mm CAN GET PAST THIS POINT!!!!!

layer #4 > .7-1.7mm > ( 1.2mm nominal ) > .2mm particles cannot pass thru

Particles from layer #3 cannot pass thru layer #4.

layer #5 > 2-4mm > ( 3mm nominal ) > .5mm particles cannot pass thru.

layer #6 > 3-5mm > ( 4 mm nominal ) > .7 mm particles cannot pass thru

plenum here.

All gravel should be carefully graded with a screen that is at the bottom end of the particle size tolerance for that layer. The screen is for "grading" the substrate, it does not get put into the aquarium!!!

The smallest grain size that is being introduced at setup with this layering model, is .2 mm in layer #3. That grain size, cannot pass thru layer #4, SOOOOOOO, NONE of the carefully graded substrate that is added to the "bed" at setup can pass thru this "Gravel Membrane".

Only particles smaller than .2mm ( .008" ), can pass thru. NONE of the substrate introduced at set-up can get to the plenum.

Poor grading of the substrate during set-up, will cause there to be "fines" smaller than this, as will "borings" from animals in the "live-rock"but they can pass thru the plenum plumbing without difficulty. With feeder holes in the plenum tubing at 1.5mm ( 1/16" ), no clogging will occur.

I assume you just add a cup of sand every so often?
Thanks,
-J

If you use araganite, or other "buffering substrate", with low pH levels in the substrate, some "reduction" of the substrate will occur. I have not seen it yet in 10 mos. in my own tank, but I understand that it does occur eventually, if buffering is taking place.

I am sure you have noticed, that I have been leaning toward a non-buffering type of substrate recently, in order to avoid any potential for this occurence.

So, does that help? > barryhc :beachbum:

 

[salty joe]

The idea of cleaning a deep sand bed from underneath has been around for quite some time. To the best of my knowledge, it has never been accomplished. The gravel membrane may well change that. Only time will tell. If eveyone trying this method documents and shares their successes as well as failures, I believe a DSB with an indefinite lifespan is possible.

 

[miatawnt2b]

barryhc,
On page 8 you talked a little about pipe diameter/cross sectional area and flow. Seems to me that you can get 100% even flow through the manifold given you don't put too many holes in the manifold and given you have a proper flow rate for the 1/2" pipe. Can you explain this a bit, and do you have any specific numbers as to # of manifold holes as a function of pipe diameter and flow rate?
Thanks,
-J

 

[barryhc]

<a href=showthread.php?s=&postid=6284784#post6284784 target=_blank>Originally posted</a> by miatawnt2b
barryhc,
On page 8 you talked a little about pipe diameter/cross sectional area and flow. Seems to me that you can get 100% even flow through the manifold given you don't put too many holes in the manifold and given you have a proper flow rate for the 1/2" pipe. Can you explain this a bit, and do you have any specific numbers as to # of manifold holes as a function of pipe diameter and flow rate?
Thanks,
-J

Yes "J", If your preferences are set to 25 posts per page, which is the std, or default here at RC, then you will find a very thorough discussion and even a chart that explain # of holes relative to hole size, and much other good information. You might want to skip past the "mini-war" that starts on page 12, but that is of course up to you.

As far as flow, is concerned, you can read from page one about flow and other variables that are very important, but there has not been any conclusive reccomendation yet as far as GPH flow, for a particular tube dia..

That is part of the experimentation , that still must occur, and has more to do with "draw volume" really than GPH, and even then has to be tuned for the depth that oxygen will be drawn down into the substrate.

My own opinion on this, thus far, is that the amount of water drawn into the substrate, needs to be a volume that is limited so that the "low oxygen area is not moved down farther than about 3-4" into the substrate, and that a layer of Anaerobic activity must be allowed to remain active in the bottom 2-3" of the substrate.

I know this is getting to be a rather long thread, but, you can start reading this from page 1, and it is like a good book. There are very many valid considerations and concerns, addressed throughout the thread, and it is terrificly educational, thanks to very many posters here.

If you get bogged down or need help with an issue, just post here again for help, but I would be surprised If you can find anything that hasn't been covered.

There is still a lot of consideration and experimantation as well, necessary to really fully get a handle om the bacterial requirements and the effects of subjecting them to fluctuations in the aerobic to anaerobic conditions.

I'm almost done with getting the "adjustable-auto-wasting-volume" gizzy-bob functional that Joe and I have worked on some. I should be "wasting by the weekend.

I will report on results as soon as I can, of course.

> barryhc

 

[salty joe]

[

I will report on results as soon as I can, of course.

> barryhc [/B][/QUOTE]

I can hardly wait!

 

[barryhc]

Hey "Salty", I will get started with the wasting, very shortly now for sure. I found a "goofy-repair-thingy-bob" at the local HWS, that happens to be perfect for me with about 12 oz. of adjustability available. $6.50 . . . . The seals in it are "way-too" heavy duty to adjust with it in place in the plumbing, but the design that you began here, when a "union" is included, allows us to just remove the whole thing, in about a minute, and then adjust "on the bench".

Since I'm into "frequent wasting" for myself, I will need to automate the wasting procedure pretty soon to maintain consistency in light of my laziness, or for going on vacation, and I have some effective ideas for this, but it is premature to get into that, until I've got a log running with some test results.

Your original "valve design" is what I'm using now, and would be permanently adequate for "occasional wasters", although they just about don't need any volume control for "occasional wasting".

An interesting note here, is that IF the automated function were to fail, the "bed" should simply convert itself to DSB, and serious problems should not occur for several months, if not years, so GEEZE, it doesn't seem that dangerous.

I really don't think anything meaningful will come from the testing for at least a month, or likely longer, but I will keep a good log anyway. This is in my little hex tank, and I did not include testing "probes or collectors" when I installed it, so only nutrients and compounds can be checked in the effluent ( not oxygen ), but it will still be valuable information.

I will put multi-level water collection for testing functionality in the larger system ( 200 gal. ) when I get that far.

Thanks for the vote of "confidence".

Enough for today, and Thanks again, > barryhc

 

["Umm fish?"]

Hey y'all! Happy holidays!

Did you all see the article in this month's reefkeeping mag about hydrogen sulfide? Sounds like a great argument for frequent wasting to me. If the O2 level of the sandbed is raised temporarily every couple of hours, it would seem like it would go a long way toward breaking down H2S.

It is also seems like even if someone doesn't want to try wasting at all, it's still advisable to have a manifold under a sand bed as the safest way to drain water from a tank that might have H2S in it's bed.

Comments?

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

 

[barryhc]

<a href=showthread.php?s=&postid=6321805#post6321805 target=_blank>Originally posted</a> by "Umm, fish?"
Hey y'all! Happy holidays!

Did you all see the article in this month's reefkeeping mag about hydrogen sulfide? Sounds like a great argument for frequent wasting to me. If the O2 level of the sandbed is raised temporarily every couple of hours, it would seem like it would go a long way toward breaking down H2S.

It is also seems like even if someone doesn't want to try wasting at all, it's still advisable to have a manifold under a sand bed as the safest way to drain water from a tank that might have H2S in it's bed.

Comments?

Exaclty, also processing of phosphate occurs in this same manner. Information on this is in the "Biological Phophorous Removal" link that I have referred to before. It has been a while, I'll try to find the link again. Actually, searches on waste treatment will give a lot of similar results.

The problem here is that waste water treatment, is for "fresh water", and the bacterial strains are not "identical". They are however very similar, and I am expecting this short "oscillation" of oxygen level to give us these types of benefits.

I have been all along, since page 1, but we have covered a tremendous amount of necessary "ground" in the mean time. Our problem here is that nobody is doing it and there isn't any data therefore to support it ( for salt water ), but that certainly doesn't mean it won't work. I for one am quite certain that it will, but it isn't just automatic, and this brings us back to "draw frequency", "draw duration", and most importantly, "draw depth".

So let's see what we can find out. Maybe we can get a little extra done with our tanks over the holidays, at least me anyway.

I need to get some kind of probes into the substrate of the little hex tank to monitor oxygen. How long is an oxygen probe going to last in salt water, if it is left "in" all the time? Anybody?

Thanks "Fish", and Merry Christmas. Heh, more "new tank" pictures? > barryhc

 

["Umm fish?"]

Sigh. I'm still fighting plumbing issues. And bronchitis. The guy who's getting the live rock I'm buying didn't get it in last week, so at least I have a break.

I'm actually down to the last couple of leaks. Unfortunately, they are in the crawl space. So, crawl in and tweak ... wait 24 hours for curing on epoxy, etc. ... crawl in and tweak. Repeat ad nauseum. Murder on the bronchitis.

Water flow is outstanding, though. I need to get some more tanks, I think I'm using about a tenth of the output of the pump I have.

Anyway, all OT. Sorry.

 

[barryhc]

More tanks sounds like the ticket. That extra flow works great for BB you know!! Maybe an SPS tank, and a species tank. Is your sweetheart cooperative about this?

Best of luck, > barryhc

 

["Umm fish?"]

If I ramp up the return flow any more, it overwhelms my drain lines. I have it running through the normal two returns, plus through a spray bar all the way around the tank. Well, you've seen the pics.... I can't understand why they aren't completely handling the flow, though. There's still air coming through the lines. (There's a short section of vinyl that I haven't taped yet, so I can see the bubbles.) Maybe I'll spend some more time messing with the durso later.

Funny you should mention it, when I plumbed the return, I plumbed out a branch line that I valved and capped, just in case....

I do have a little nano tank coming for the next project, but I'm so sick of plumbing that it might sit for quite a while....

 

[barryhc]

I think that there is a "standing-bubble" condition that occurs in some drain lines. Kind of like vapor lock in a fuel line in older cars.

I have a CPR overflow, which is no great shakes, but it has a little tube that extends down into the drain pipe to reduce "flushing" sounds, which it does. The interesting thing though is that it also acts like an overflow "safety" by accident. If something is blocking flow enough in the outer box, ( like when I put some filter floss in there a while back ) the water rises, UNTIL it gets to the top of this tube, and then when water starts going into the tube, the water level in the outer box, drops until air is entering the tube again.

Now this seems like common sense, BUT, when I cover the top of this little tube, the water level "drops like a rock". So, when air is allowed into the drain tube, it drains slower, but when no air is allowed, it drains VERY much faster. This means water will flow faster, even through a consideranly smaller opening, so long as no air gets into the tube.

So, what to do? I have a little invention in the back of my head to handle this problem, but it is far from ready.

I think people who run dursos, probably have some kind of solution for this. Maybe you can find some info in a DIY thread for durso style drains. IF I am thinking right here, you should be able to cover the top ( open ) pipe with your hand, and see the flow go up a lot, until the water gets down to the side pipe, and gets real noisy again.

Let me know. > barryhc

 

[SHIRDI]

Ok, I've read all this thread. Not going to claim to understand all that is said. I don't know if my experienc is helpful. But I have run for 7 years a modified Plenum/Refug based on the Smithsonian Institutions reef tank. I have a 135 gal display tank. For the Plenum/Refug I use a 30"x36"x18" tank with a "v"shaped bottom that goes from the 30"x36" foot print to a 4"x4" bottom with a 2"drain hole with a valve on the end for easy purging of plenum. I have a total of 16" from bottom of "v" to top of the graval. (all of this space is not graval.)

I put a 8"x8" peice of egg create with screening over it on the bottom of the plenum. Put 4" of sand ontop of that and then another layer of screening. On top of that I put 3" of a courser graval followed by another layer of screening. Ontop of that I have 3" of mixed rubble and sand. Every year for the past 4 years I have added 20lbs of "GARF" Live Sand Activator to replace the subsrtate that breakes down.

I drain 10 gal from plenum/refug every 2 to 3 months using the valve installed on bottom of refug. I didn't start to drain the plenum/refug until the tank was set up for 18 months. Ill explain later why I waited 18 months.

The material I pull out would be decribed as a thick soup with some fine sand mixed in. I find lots of worms in the soup. When I first smell the drain soup water it smells like sweet fishy dirt. (if that makes sence) After about 1 hour it begins to smell like rotten eggs-sulpher.

The Phospahtes in my tank started at 4(old, crapy Ro unit) and after 8 months with 0 water changers, only top off water added the Phos were at 0. At 16 months the Phospahtes began a slow climb from 0 to 1.5 over 2 months. Thats when I stared to drain 10 gal from Plenum/Refug. After that No Phospahtes in 5 years.

Next drain I will test the soup water for Phos, PH, and Nitrates. Any thing else I should test the drained water for.

equipment- 3x 400watt 10,000k MH, 2x 30 watt Blue actinic 2x 40 watt 03 actinc- 03 actinc runs 16 hours, Blue Actinic runs 12, 1 400 watt MH for 8 hours and the other 2 MH on for 3 hours.
-rio2100 return for sump/refug/plemun
-2xIwaki MD30RXT for a circulation pumps returns with PVC spray bar 3 " from bottom and running entire lenght of tank 6'
-1x 48" tall 6" diameter venturi skimmer using Iwaki MD40RXT main and rio 1700 for counter curent.
-2X rio 1700 on wave maker.
-I add Seachem Reef Calcium, Reef Complete, and Reef Plus 2x per week. And top of tank with 3 gal per week.
- 1hp chiller

Temp 80
PH 8.3
Sal 1.025
Calcium 440-460
Alk 8
Phos 0
nitrates o