DSB Heresy

[docjay]

Thanks. The sand bed/plenum area is 3' by 2'. I may have to do a few more than 40 to cover the whole bed. Do you drill the holes on the top, bottom or sides of the pipe?
Also I was thinking of hooking it up to a dual peristaltic pump. That way I can simultaneously replace with fresh saltwater whatever I remove from the sand bed. Do you think this will work or will the flow be too slow?

Jay

 

[seaspook]

Great tread and a great idea. I just found it and spent the last couple of hours here. In my 30 years of keeping salt water fish and corals I have used an evolution of systems from sugar tanks to dsb's. I think you may be on the road to the next level.

Couple of questions

I am moving a 75 gal tank (only a few feet) with a 5" dsb. This tank has been running with a heavy load and over feeding for the last five years and I believe I am overdue for a crash. The existing sand is sugar size and I understand the need for the larger size.

Questions.
Should I transfer any of the existing sand to ease the recycle shock ? Or should I pre cycle some of the larger grain sand in my sump/refugium for a few weeks b4 I make the move?

Can someone find a web link to the type of fabric you are using. I went to HD and Lowes and could only find the tarpaper /felt looking stuff. I am not quite sure what I am looking for.

You mentioned somewhere back a few dozen posts that you put some extra pvc pieces in the blank areas to keep the fabric from crushing in around the system plumbing. Is this creating an area where you are sucking water from the chamber you have created and not the sand? My understanding is that this is something to try to avoid.

As an observation, I believe that the water volume that is removed in each evacuation should be related to the volume of the CPW system you are building. I would think that you would want to remove at least the amount of water that it would take to fill all the pipes and overflows , but not much more. May or may not be important, but I think the guy with the 200 gal tank and miles of pipe would need to purge more than the person with the 30 gal system.

Thanks

alan

For us old hippies, what you are trying to create is the BONG principle. That sudden shot of air pulled through a small hole to clear the tube in one quick blast.

 

[ldrhawke]

Couple of questions

I am moving a 75 gal tank (only a few feet) with a 5" dsb. ............

Questions.
Should I transfer any of the existing sand to ease the recycle shock ? Or should I pre cycle some of the larger grain sand in my sump/refugium for a few weeks b4 I make the move?

I WOULD DO THE FOLLOWING TO SEED THE NEW SUBSTRATE. AS YOU ARE PULLING OUT AND STIR UP THE SUGAR SAND, I WOULD ADD FIVE OR 10 GALLONS THE DIRTIEST WATER YOU PULL OFF TO THE NEW TANK AND SUBSTRATE FIRST. THEN TRANSFER THE REST OF THE OLD SALT WATER TO THE NEW SYSTEM.

Can someone find a web link to the type of fabric you are using. I went to HD and Lowes and could only find the tarpaper /felt looking stuff. I am not quite sure what I am looking for.

GO TO THE PLANTS AND NURSERY SECTION OF HD. THE MATERIAL COMES IN LARGE ROLLS AND IS USED AS A DRAINAGE BARRIER TO HOLD BACK DIRT AND ALLOW WATER TO DRAIN. IT IS A POLY FELT.

You mentioned somewhere back a few dozen posts that you put some extra pvc pieces in the blank areas to keep the fabric from crushing in around the system plumbing. Is this creating an area where you are sucking water from the chamber you have created and not the sand? My understanding is that this is something to try to avoid.

GOOD POINT AND OBSERVATION. I FIGURED THAT EVEN WITH THE INSERT IGNORE IGNORES BETWEEN THE PIPES THE WEIGHT OF THE SUBSTRATE WOULD STILL COLLAPSE AROUND THE PIPES AND CAUSE NUMEROUS SMALL ZONES WHICH WOULD STILL EQUALIZE THE FLOW. BUT, YOU ARE CORRECT IN WHAT YOU SAY.

As an observation, I believe that the water volume that is removed in each evacuation should be related to the volume of the CPW system you are building. I would think that you would want to remove at least the amount of water that it would take to fill all the pipes and overflows , but not much more. May or may not be important, but I think the guy with the 200 gal tank and miles of pipe would need to purge more than the person with the 30 gal system.

AGAIN, A GOOD POINT. AS I STATED AS MORE PEOPLE USE THE CPW APPROACH THE CONCEPT WILL BE TWEAKED.

Thanks

alan

For us old hippies, what you are trying to create is the BONG principle. That sudden shot of air pulled through a small hole to clear the tube in one quick blast.

SORRY AFTER MY TIME, BUT I AM SURE YOU HAVE JUST REACHED A WHOLE NEW AUDIENCE....:strooper: I CAN SEE THE MJ SMOKE CURLING FROM THE CPW PIPING AS I TYPE THIS....:lol:

 

[vmichael]

I am changing my 55 Gal to a 110 Gal tank in the next couple of weeks and I'm thinking on using this principle.

Think I can plumb it this way?

I currently have 4 holes in the 110g tank 2 in each corner.

2-Overflow in to sump and 2 for flow back into the tank.

I was thinking of plumbing a CPW system out of one of these holes with a T and 2 valves.

I shut of the system so no water is circulating.
Close the valve for the outflow and open the valve for the CPW drain. Reverse to resume normal circulation.

Essentially there would be a T coming out of the bulkhead at the bottom of the tank with 2 pipes 1 going up and over the overflow box for regular circulation and the other going to a pipe system with drilled holes on the bottom of the inside of the tank (CPW).

This way, I could have the best of both worlds. A standard DSB and an optional CPW.

Any thoughts?

 

[salty joe]

This is what a knowledgable friend had to say.

Well, it IS a great idea in theory, but then you have to look at the
whole picture. A Plenum works much like the DSB, in that it utilizes
anaerobic (oxygen free) bacteria to consume nitrates. What's going to
happen as you drain that plenum area? It's going to pull oxygen-rich
water through your previously anaerobic zones and wipe out most of your
anaerobic bacteria. This results in the shut-down of your nitrate
reduction capacity until it can recycle itself out.

He went on to say that would create a stressful environment for corals.

 

[darrellh]

Salty Joe,

ldrhawke has explained this a couple of times in this thread (I know its hard to read everything that has transpired). Basically he's conceding that the bed may not biologically operate as a denitrification filter. What he does claim is that nitrates and phospates will tend to be concentrated in the lower portions of the bed where they will be removed mechanically (not biologically).

Darrell

 

[rpgraff]

What he does claim is that nitrates and phospates will tend to be concentrated in the lower portions of the bed where they will be removed mechanically (not biologically).

I tried skimming through this monster to find out if there was any testing done for concentrations removed. I didn't find it........Is this a theory or is there any actual data supporting that?

 

[Chicago]

note,, not all denitrifying bacteria work in abscense of total oxygen free enviroment. some work in lower oxygen levels. i dont believe that such a sytem would killl existing nitryfying bacteria becasue of small water removal. our beds are constantly changing in small ways. some bacteria in one area are one kind and a year late maybe a defrrent dus to tank changes. what we need is testing .. on a scientific level on this theory.

 

[ldrhawke]

I tried skimming through this monster to find out if there was any testing done for concentrations removed. I didn't find it........Is this a theory or is there any actual data supporting that?

Well, it IS a great idea in theory, but then you have to look at the
whole picture. A Plenum works much like the DSB, in that it utilizes
anaerobic (oxygen free) bacteria to consume nitrates. What's going to
happen as you drain that plenum area? It's going to pull oxygen-rich
water through your previously anaerobic zones and wipe out most of your
anaerobic bacteria. This results in the shut-down of your nitrate
reduction capacity until it can recycle itself out.

Both Chicago and Darrellh have answered your questions. I'll add a few points.....

1. Hook up a CPW system and smell the water that is initially discharged. You will not question it's being highly anoxic or if it is good or bad to remove again.

2. Since hooking up my CPW I have not had any measurable nitrates.

3. In commercial waste treatment the simultaneous nitrification and de-nitrification often takes place inside the same single tank. Denitrification starts to takes place in any zone depleted of oxygen. As Chicago has said, there is no reef keeping imaginary line of either / or, as many in the hobby try to make. It is simply a transitional zone where one or the other start to dominate. Both types of bacteria are present through out the substrate waiting to dominate, based on available food source and oxygen or lack of.

If oxygen is depleted in a oxic zone, which can take place in as little as 15 to 20 minutes, denitrifying bacteria will being to dominate.

I believe that when CPW is used, the whole bed depth is being feed with a positive movement of fresh food source through through out the bed depth and both oxic and anoxic processing is increased.

In addition, if bound up phosphates are being released because of the drop pH in the bed, they are hopefully being drawn off with the CPW.

I believe that most DSB's go bad when sulphide reduction takes over and dominates. I have read numerous comments on the RC list from reek tank keepers who have been forced to rebuild their tanks because of the black sulphide reducing zones in the DSB expand and move to with an inch of the top of the bed.

In any case you have established a positive flow into the bed and out through the CPW. If the nitrification cycle has not been completed, what remains is being drained out of the system. The suphide odors, you initally smelled from a system that is not drained at all, disappear.

 

[Chicago]

the idea of a CPW is not all that new. years agon when there was the start of phlenum systems i beleive many toyed with the idea. some that were running under gravels disconnected the lift tubes from the pwer heads and allowed one to stay and capped the other. the one that stayed was used to remove waste water. now what the systems had benifits of i dont know. i think the fear was that the experts at that time were saying that the water in the phelnum was a re cyle zone if set up correctly. go bakc about 7 yearas or more and you might find an article in FAMA to this effect. then later there was the theroy that phlenums wer sink holes for waste products. then comes the DSB theroy of large deep sand beds not just an inch or two.
so with this in mind, and this is what kills me. i set up my 300 gallon sump, rubermaid with a system made out of pvc pipe that is all connected and serves as the phlenum support below the eggcrate. theis piping is then channeled out a bulkhead on the botton side of the sump. all good to go. then i made the mistake. i started reading too much on the bb hear. next thing you see, i remove the phlenum before adding the fine sand and just dump 4 inches into th sump and go DSB. now i'm thining i should have gone for it. although my plan was to simpley do 50 gallon water changes from the phlenum water., not slowly but in one shot. of course the sand area was large. now that i think about it. i will tag along and go looking for the pvc system i stored up in the attic.

just my two cents. gook luck with the system keep us posted
just my

 

[DennisRB]

I haven't read the whole thread yet but... Wouldn't the chemical and biological reactions in the CPW DSB be totally irrelevant as any water that has been treated by the DSB will end up in the sink anyway? All of the DSB treated, denitrified water goes in one direction... towards the sink.

Interestingly, I immediately though of a CPW type idea as soon as I first heard about plenums. I thought a stagnant volume under a DSB would be quite useless.

 

[rpgraff]

1. Hook up a CPW system and smell the water that is initially discharged. You will not question it's being highly anoxic or if it is good or bad to remove again.
2. Since hooking up my CPW I have not had any measurable nitrates.

I don't doubt that, I don't think I want to stick my nose in the bottom of a 6" DSB, or break open a piece of live rock and take a strong wiff either. All that it shows is anoxic activity is taking place.

As far as your nitrate level, I am assuming you had traces before you tried this method? My earlier question was in relation to actual data, that removing some of the water under your plenum was removing water with concentrated nitrate levels in relation to what just a normal water change would remove. I don't doubt that the stuff smells like cr*p, but is it concentrated with nitrates???? I'd want to see some actual testing data before I made that assumption. I wonder if it is more likely that the method simply makes nitrate reduction more efficient?

3. In commercial waste treatment the simultaneous nitrification and de-nitrification often takes place inside the same single tank. Denitrification starts to takes place in any zone depleted of oxygen. As Chicago has said, there is no reef keeping imaginary line of either / or, as many in the hobby try to make. It is simply a transitional zone where one or the other start to dominate. Both types of bacteria are present through out the substrate waiting to dominate, based on available food source and oxygen or lack of. If oxygen is depleted in a oxic zone, which can take place in as little as 15 to 20 minutes, denitrifying bacteria will being to dominate..

Well, of course, the same thing happens inside live rock. it is interesting that a system I am going to try out advocates using a certain substrate in a filter, 3 hours running 3 hours off, claiming it creates alternating aerobic and anerobic cycles in the filter.

In addition, if bound up phosphates are being released because of the drop pH in the bed, they are hopefully being drawn off with the CPW.

hmmm, interesting thought, but if this is happening with phosphates, what is to prevent them from escaping up through the bed into the water column in between periods of drainage? Or do you drain constantly? Then again we don't know for sure the mechanics anyway I guess.

 

[ldrhawke]

" Just Because I'm not afraid
to voice my opinion, doesn't
mean you should take it as gospel.....I really don't want the responsability ;-) "

Rick,

Your tag explains everything. If I were you I'd wait until we run our CPW systems for a few years and collect all the data for you. :rolleye1:

 

[rpgraff]

Was that a brush off??????

 

[Shoestring Reefer]

I haven't read the whole thread yet but... Wouldn't the chemical and biological reactions in the CPW DSB be totally irrelevant as any water that has been treated by the DSB will end up in the sink anyway? All of the DSB treated, denitrified water goes in one direction... towards the sink.

hmmm, interesting thought, but if this is happening with phosphates, what is to prevent them from escaping up through the bed into the water column in between periods of drainage? Or do you drain constantly? Then again we don't know for sure the mechanics anyway I guess.

Was that a brush off??????

Clearly, neither one of you have closely read this entire thread.

Communication 101: How to communicate with a CEO.
1)When communicating with CEOs, you must start your first post to the thread with a complement to the CEO.

2)In each additional post:
A) Endorse, show support of, or in some way defend the CEO's agenda.
or
B) You may question the CEO's idea in a way that clearly indicates that you have less understanding than the CEO, and the post must be written such that it is clear that you expect to be corrected.

3)When corrected by the CEO:
A) Offer your thanks
B) Again indicate that you have less understanding than the CEO
C) Return to 1).

 

[brentp]

Shoestring-
That's pretty funny. And my wife says I'm pretty full of myself.

 

[rpgraff]

your introduction of a little humor is appreciated shoestring....

I was just taken back at the reference to my signature quote (which is ment tongue in cheek by the way), as a dismissive attempt to not discuss the questions I have.

All I'm trying to do is get a better understanding of the process and what it does or does not accomplish.

 

[Frank Mularo]

Clearly, neither one of you have closely read this entire thread.

Communication 101: How to communicate with a CEO.
1)When communicating with CEOs, you must start your first post to the thread with a complement to the CEO.

2)In each additional post:
A) Endorse, show support of, or in some way defend the CEO's agenda.
or
B) You may question the CEO's idea in a way that clearly indicates that you have less understanding than the CEO, and the post must be written such that it is clear that you expect to be corrected.

3)When corrected by the CEO:
A) Offer your thanks
B) Again indicate that you have less understanding than the CEO
C) Return to 1).

I like the ideas here, but you're right, it seems ldrhawke suffers from a slight case of Dr. Ron-itis.

 

[robwsup]

LMAO |D

 

[ldrhawke]

I'm sitting in a hotel room across country in Portland and just found time to log on to RC. I find it very humorous how some people fall down and cry like 4 year old kids when they get responded too in kind. Grow up kids....or better yet learn some manners.