DSB Heresy

[Shoestring Reefer]

Strandedthinker,

What is the purpose of each mode of operation? What is the difference between "Implementing CPW drain" and "Normal Functioning"?

 

[ldrhawke]

Ive started the construction of my CPW. Ive worked off your original plans of the grid for the substrate but have created my own piping system in the back, I believe.


..................

EDIT: text thing didnt work so I uploaded an MS paint mockup.

Left side is Return comign from pump
Right is goint to and from Drain

All I see is an H with three red dots in your attachment.

I'm not following the flow and do not understand the concept of what you are trying to do.

 

[Shoestring Reefer]

All I see is an H with three red dots in your attachment.

I think his earlier post explained it

I will label each ball valve as follows:
Drain- D
Return- R
Middle- M

Left side is Return comign from pump
Right is goint to and from Drain

I'm not following the flow and do not understand the concept of what you are trying to do.

Me, either.

Strandedthinker-
I'm guessing you have the plenum piping connected to the pump return piping *edit: but seperated with a valve* so you can just run his return pump normally and not drain (in "Normal Functioning" mode) and then run the pump while draining (in "Implementing CPW drain" mode).

You have a third mode called "Flushing Pipes" that looks like you will pump into your plenum with your return pump while the drain is closed. Sort of like a UGF. Is this what you intended?

 

[Strandedthinker]

I will upload some pictures, unfortunately hawke never send me back with instructions so ive worked from two of his images.

Hawke must be able to do the following with his plenum piping: drain from then and flush. Draining is easy, you just make the grid with a pipe coming out and over the tank. But creating the initial siphon he said was done with a pump by first flushing. In one of his pictures he shows that the pump is also connected to the drain line. Instead of buying another pump I used the one I had. Hopefully my picture will explain it better.

Below is the functions of the lines and ball valves:

Normal Operation
The left piping will be connected to the pump in my sump. The ball valve (1) for this line will always be open. The ball valve (2 and 3) connection the drain line and return line will be closed.

Draining
The same as normal operation except the drain ball valve (3) will be open. I unfortunately dont want to have an X10 automatically do this for me, I will do it manually.

Flushing
Opposite of draining. Valves 1 and 3 are closed and valve 2 is open.

 

[ldrhawke]

I will upload some pictures, unfortunately hawke never send me back with instructions so ive worked from two of his images.

Hawke must be able to do the following with his plenum piping: drain from then and flush. Draining is easy, you just make the grid with a pipe coming out and over the tank. But creating the initial siphon he said was done with a pump by first flushing. In one of his pictures he shows that the pump is also connected to the drain line. Instead of buying another pump I used the one I had. Hopefully my picture will explain it better.

Below is the functions of the lines and ball valves:

Normal Operation
The left piping will be connected to the pump in my sump. The ball valve (1) for this line will always be open. The ball valve (2 and 3) connection the drain line and return line will be closed.

Draining
The same as normal operation except the drain ball valve (3) will be open. I unfortunately dont want to have an X10 automatically do this for me, I will do it manually.

Flushing
Opposite of draining. Valves 1 and 3 are closed and valve 2 is open.

Looks good.....that'll work.

Only one comment, I would make sure the drain line extending below valve 3 extends below the refuge water surface or is necked down a smaller line size to keep it from breaking vacuum and stop draining.

 

[Strandedthinker]

What do you mean by refuge water? The sump correct?

 

[ldrhawke]

Right......

 

[nameless]

OK, I have a bunch of points, from all 15 pages of this, so please bear with me.

First, if you're only draining a quart or gallon, you're barely draining out the volume of the pipe. In that case, smelling the water, imo, is not a good indicator of anything, since it's been sitting in the pipe for an undetermined period of time (assuming you aren't completely draining it each time).

Second, I think we've established that the DSB's functionality is basically replaced in this system. What we've got here is analogous to installing a drain in your bathroom, then just hosing it off and letting the 'waste' run to the drain. Whether a DSB is present or whether it's just some crushed coral probably doesn't make a whole lot of difference in the CPW. I think, though, that if you wanted to have a true DSB with CPW you could, but you wouldn't be able to drain as often as idrhawke describes. If the true purpose of CPW is to lengthen the life of a dsb, why not only drain off on a bi-weekly or monthly basis? This way, your dsb is still functioning normally, but you're draining off the nastiest sludge on a regular basis. This allows the DSB to do it's job, but still keeps it from building up a dangerous amount of anything.

Third, idrhawke, I think your tank is dangerously overstocked.

Fourth, an idea to give some control to an experiment. Has anyone ever used a syringe to try to extract water from their DSB for testing? Especially mature DSBs? It would allow for testing without disturbing the setup, and may give us some idea of what was going on in those out of way places at the bottom or our tanks.

Fifth, has anyone actually taken the piping, once it's set up, and ran water into it to verify that it actually does come up with equal pressure from every hole? It's not that I don't trust people's opinions of fluid dynamics, etc etc, but, I think an actual experiment might show some interesting things. Especially when you consider the volume in that entire pipe.

Sixth. why sand? Since we've established that the dsb is really not functioning as a dsb in this scenario, what if you just put the pipe in, exactly as you would in a CPW, except without screening. You'd drill the holes near the bottoms of the pipe, and just put in enough CC to cover the pipes. Then, you would just do water changes out of the drain instead of out of the water column. this allows you to get right at the wastes, similar to a CPW, but without a lot of the hassle. The holes are less likely to clog, being somewhat inverted. You're still pulling water from the most concentrated wastes in the tank. What you're basically doing is exactly what a skimmer does, ie grabbing the wastes and removing them before they have a chance to break down.

Then again, I'm not a chemist, not a CEO, not a Dr., not a marine biologist, and I don't know anything about fluid dynamics, so there it is.

Finally, it does occur to me that anything can be taken personally probably will be taken personally by someone, even if you surround it with smilies. It might be better decorum to just ignore anything you might construe as a personal attack and keep the discussion about the topic. It's interesting enough without the sideshow.

 

[ldrhawke]

Nameless....some good observations.

OK, I have a bunch of points, from all 15 pages of this, so please bear with me.

First, if you're only draining a quart or gallon, you're barely draining out the volume of the pipe. In that case, smelling the water, imo, is not a good indicator of anything, since it's been sitting in the pipe for an undetermined period of time (assuming you aren't completely draining it each time).

Question? What would make the waste water in the pipe any different than what is on the bottom of a DSB?


Second, I think we've established that the DSB's functionality is basically replaced in this system.

Not replaced...improved upon

What we've got here is analogous to installing a drain in your bathroom, then just hosing it off and letting the 'waste' run to the drain. Whether a DSB is present or whether it's just some crushed coral probably doesn't make a whole lot of difference in the CPW. I think, though, that if you wanted to have a true DSB with CPW you could, but you wouldn't be able to drain as often as idrhawke describes. If the true purpose of CPW is to lengthen the life of a dsb, why not only drain off on a bi-weekly or monthly basis? This way, your dsb is still functioning normally, but you're draining off the nastiest sludge on a regular basis. This allows the DSB to do it's job, but still keeps it from building up a dangerous amount of anything.


I don't agree with your analogy, but I do agree with your conclusion! You understand the purpose of CPW, now we only need to reach an understanding of optimum frequency!

Third, idrhawke, I think your tank is dangerously overstocked.

You may well be right. Please expand on the danger. It sounds serious. !


Fourth, an idea to give some control to an experiment. Has anyone ever used a syringe to try to extract water from their DSB for testing? Especially mature DSBs? It would allow for testing without disturbing the setup, and may give us some idea of what was going on in those out of way places at the bottom or our tanks.

I sample and test this way every time I drain through the CPW plenum. What is removed is from the bottom of the DSB, why do you need a syringe?

I think what you will find in the bottom of a mature DSB has been expressed hundreds of times over the years in RC. A stinky anoxic mess.

Fifth, has anyone actually taken the piping, once it's set up, and ran water into it to verify that it actually does come up with equal pressure from every hole? It's not that I don't trust people's opinions of fluid dynamics, etc etc, but, I think an actual experiment might show some interesting things. Especially when you consider the volume in that entire pipe.

That topic has be beaten to death on this thread

Sixth. why sand? Since we've established that the dsb is really not functioning as a dsb in this scenario, what if you just put the pipe in, exactly as you would in a CPW, except without screening. You'd drill the holes near the bottoms of the pipe, and just put in enough CC to cover the pipes. Then, you would just do water changes out of the drain instead of out of the water column. this allows you to get right at the wastes, similar to a CPW, but without a lot of the hassle. The holes are less likely to clog, being somewhat inverted. You're still pulling water from the most concentrated wastes in the tank. What you're basically doing is exactly what a skimmer does, ie grabbing the wastes and removing them before they have a chance to break down.

same answer I gave for your second point

Then again, I'm not a chemist, not a CEO, not a Dr., not a marine biologist, and I don't know anything about fluid dynamics, so there it is.

Finally, it does occur to me that anything can be taken personally probably will be taken personally by someone, even if you surround it with smilies. It might be better decorum to just ignore anything you might construe as a personal attack and keep the discussion about the topic. It's interesting enough without the sideshow.





You're far too serious...lighten up. This is a hobby. It's supposed to be fun. I notice a lot of you Northerners start to get a little testy on RC waiting for the sunshine to come this time of year...

I have posted on my WEB site the CPW drawing that has some modifications to further hopefully improve upon CPW. I'm happy to say the initial results of zero measurable nitrates and phosphates is encouraging. Even with my heavy bio load.

Thanks for your comments

 

[Shoestring Reefer]

Sixth. why sand?

Why would you bother without sand? The DSB does not support CPW; rather, CPW supports DSB.

Clever name, by the way.

Originally posted by ldrhawke I notice a lot of you Northerners start to get a little testy on RC waiting for the sunshine to come this time of year... [/B]

Cabin feaver. 100 years ago northerners use to kill their families in the middle of winter, now we just take it out on people from Florida.

 

[pr4mncplus]

Mike,
That last comment about people from Florida had me on the floor doubled up in laughter!

 

[vmichael]

Mike,
That last comment about people from Florida had me on the floor doubled up in laughter!

Yeah! We get a kick out you northerners when you come down here and enter the highway and go directly into the left lane and slow down to 35 mph.

Luckily, most of us don't carry guns!:eek2:

 

[nameless]

My comment about the syringe was for people without CPW. What I meant was that we could have people test their DSBs after periods of 1,2,3,4 and 5 years, and test what came out. We could compare with CPW waste water and see what we were looking at. I think it would be very instructive.

My point about why sand is related to the fact that if you're removing a lot of water from the sand, you're bringing oxygenated water in behind it, so you're probably getting very little denitrification going on. More then that, you're basically just removing the wastes before they get to break down, like a skimmer. If that's the case, then crushed coral just seems like it'd be a lot easier to work with, because you wouldn't need to worry about clogging, and you'd worry less about channelling.

Oh, and I hate Florida, it's too flat, too hot and too humid. Give me the Dominican Republic any day

 

[Strandedthinker]

Since the Dominican isnt hot and humid.

 

[ldrhawke]

we could have people test their DSBs after periods of 1,2,3,4 and 5 years

Without the test being under identical controlled procedures in a lab set up I am not sure what the results would prove. Plus, it doesn't take five years to develop anoxic soup in the bottom of a DSB. How bad that soup becomes, and how quickly it will cause a tank to flip, has a lot of variables. The point is we do know it happens and it can get out of control.

Even the most pro-advocates of DSB's, including Dr. Ron, acknowledge it happens, an cannot agree on a solution or if there even is a solution. Dr. Ron advocates it is caused by the life he recommends seeding in the sand dying and not being replaced on a regular basis or not varied enough. I contend, if you need to re-seed new life into the bed because the worms and critters die, you have problems anyway. The life in DSB should flourish and never need to be reseeded. Maybe they don't like that anoxic soup either. My coarse crushed coral DSB is loaded with sphegatti worms and life. I can see worm burrows all the way to the bottom next to the clear acrylic. They don't seem to mind CPW in the least.

Plus, I do not believe a few worms in a bed produce adequate exchange between the surface and bottom to be enough to keep the bed from flipping and develop creeping anoxic soup.

My point about why sand is related to the fact that if you're removing a lot of water from the sand, you're bringing oxygenated water in behind it, so you're probably getting very little denitrification going on. More then that, you're basically just removing the wastes before they get to break down, like a skimmer.

Question for you! Why is it that everyone worries about too much movement of fresh food into the anoxic zones, and not worry about starving it? At least with CPW you have a method of controlling flow rates into the bottom of a DSB and feeding it. You have no control of worms and critters in a DSB. Dr. Rons already states they die and need to me supplemented with new ones every year. Why do they die if a conventional DSB is such a good place to live? Maybe they don't like that anoxic soup either?

My point about why sand is related to the fact that if you're removing a lot of water from the sand, you're bringing oxygenated water in behind it, so you're probably getting very little denitrification going on. More then that, you're basically just removing the wastes before they get to break down, like a skimmer.

Again a question! How do you know that CPW brings too much oxygen into the bottom of the bed? The oxic zone and bacteria in the upper layers of the DSB eat the waste and use up the oxygen. With in 30 minutes oxic layers can deplete enough oxygen to allow de-nitrification to proceed. In a municipal WWTP it is the basis for design to denitrify in the next stage after high rate aeration.

I believe coarse crushed coral sand is a better media because it more readily allows fluid movement in the DSB. It doesn't stop the bottom of a DSB from going anoxic and denitrifying. Why don't you question the ability of Live Rock to de-nitrify?

Personally, I believe whole concept of zero flow through a Reef Tank DSB, depending wholly upon worms to turn over the layers, is flawed and wrong. That is not to say that DSB's don't work at all and don't help keep nitrates low. That is not to say a conventional DSB with low bioloading they can't last a long time.

Conventional DSB is like a Cult movement with the winners being the guys that can say on RC, "I've had my tank set up for 3 years or 5 years and it hasn't flipped yet". I believe there may be a better way. Why not just go BB...because I believe, like live rock, the additional biological activity in a DSB can make reef keeping easier.

Sure, you can have too much flow with CPW and interfere or reduce the efficiency of de-nitrification. That is why I'm playing with a separate denitrification system for continuous flow through the bed, which may also help to transport phosphates in the bed. As I have seen and others have now also seen, when using CPW, it appears more phosphate comes out of the bed using CPW than is in the water column

But the flip side with conventional DSB's also has potential problems, no flow and you can have a garbage can full of anoxic waste pushing to the surface. If it breaks through or if the bed is stirred up, it can cause havoc and start the death spiral. A few fish or coral die and the they over load the whole biological system and everything dies in a downward spiral.

Oh, and I hate Florida, it's too flat, too hot and too humid. Give me the Dominican Republic any day

Thank God.....Brer Fox,ââ"šÂ¬Ã¢"žÂ¢ , Brer Rabbit sez please pass the word around to everyone you know about how bad Florida is .....too hot, too humid, and too flat. . You made my day. .:rollface:

 

[Shoestring Reefer]

Yeah! We get a kick out you northerners when you come down here and enter the highway and go directly into the left lane and slow down to 35 mph.

We're scared to drive in the right lane because that's where all the on ramps and exits are. Then we drive 35 instead of 70 because we are spending half of our time looking at our mapquest directions.

Same thing happens up here with out-of-staters, but also with some of the locals. Especially the older ones. We still have a few older people who remember when they used to put a piece of leather over electrical outlets to keep their electrical bill down. They didn't want to let the electicity out.:rolleye1:

 

[ldrhawke]

CPW UPDATE

CPW UPDATE

Updating my CPW and CPW effluent polishing system testing experimentation.

The purpose is to find a way to further improve upon CPW by using a continuous low flow rate removal from the CPW system and recycle it back into the tank. The idea is to have an easy to operate, responsive, and low maintainence reef system that is forgiving of over feeding or shock loads. This may not be necessary with an SPS tank with minimal live stock.

In my normal operation of CPW I was flushing a couple of gallons/day of water into the drain, and not attempting to recover or recycle the water. I ran it at different rates and frequency of wasting. My regular water 25% by-weekly changes continued to be through CPW.

The water quality in my tank water column showed barely detectable Phosphate and Nitrate when I carefully fed the tank every other day. If I fed daily with increased feed rates, low readings of both on the Salifert test, would start to show up and increase to as high as 25ppm nitrates and 1 to 3 ppm phosphates. These readings would slowly return to non-detectable with greatly reduced feed rates. The DSB/CPW was definitely de-nitirfiying and phosphates were being removed.

I felt I was starving the fish and coral and desired to find a method that would make the system even more biologically responsive to heavier feeding and biological surges and still be able to rapidly control phosphate and nitrate waste.


1) Initially, I simply set up the CPW to drain back into the sump with a high drip rate, that was about 25 G/Day, to test the DSB/CPW ability to respond. I was hoping continuous flow and feed rates through the DSB would increase the biomass in the DSB and improve its biological processing rate. During this testing I fed daily a couple of frozen cubes/and dry food.

After a week at this flow rate the water column tested at about 15ppm nitrate and 1 ppm phosphate. What was being dripped back into the tank was about 10ppm and 1.5ppm respectively. Running the dilution math, this approach was working but it would take awhile. Nitrates were being reduced and it appeared phosphates may have been going back into solution in the DSB to allow removal. It was going to be a slow process.

The idea of returning any nitrate or phosphate back into the water column bothered me. Looking back, I should have continued to test this approach for at least 30 to 60 days and played around with the flow rates. I may go back and do that later.

The CPW drawing on my WEB site goes into layout and components used to polish the CPW discharge. During this test I continue to run my modified PM skimmer, O3, and my calcium reactor. Calcium over 400, Alk 5, pH 8.3, temp 80

2) I decided to attack the phosphates immediately using RowaPhos in a DIY fluidized bed filter made with of 4" acrylic tube and plastic wine glass, the wine glass was used to make an elliptical cup bottom. It sits in my fuge. It has its own very small pump and is self contained. Its discharge flow is over the top of the filter back into the fuge. No piping or leaks to worry about. Warning to anyone using RowaPhos in a fluidized bed filter, a very low flow rate is critical. Otherwise, you will have a very orange cloudy tank from the ferric dust. Over the last month my phosphates have reduce to zero, in the water column and CPW discharge. This phosphate control approach appears to me to be the most response, effective, and best way to eliminate phosphates from a heavily feed system. It is easy to run and maintain. I simply add a couple of teaspoons of fresh RowaPhos to my filter every couple of weeks. When I start to detect phosphates and/or when my bed stops boiling and rolling from the increased amount of RowaPhos, I will empty the filter and start over with about a cup of new RowaPhos. Phosphates are no longer an issue. This system should be able to run for months unattended now that my phosphates are zero .

3) Next nitrates. I built de-nitrification filter for the CPW discharge. I have made some component modifications to the drawing. For my media containers I selected two LifeGuard Chemical filter canisters. They came with a base and can stand alone and are easy to disassemble or refill media, and fit neatly onto my cabinet shelf. They are plumbed in and out using only 1/4ââ"šÂ¬Ã‚ poly tubing with the low flow rates and are easy to move around.

In the first stage, I used 100ââ"šÂ¬Ã¢"žÂ¢ roll of stiff black 1/4ââ"šÂ¬Ã‚ nylon tubing to positively reduce oxygen. I never took the tape off the roll and I used it as I received it.

For the second and third stage I used the LifeGuard canisters. I ordered sulphur balls for the 2nd stage and primary de-nitrification, but they were back ordered and I still have not received them. In the third stage I placed carbon. Since I had not received the sulphur balls, I decided to start it with carbon also in the second stage. Since I would need to be fed a carbon food source for de-nitrification now, I used my dosing pump to feed dilute alcohol.

I allowed the system to run wide open with a rapid drip rate only using gravity feed, about 30 gpd, without any control valve. I did install a normally closed solenoid valve in the feed line for power outage. I don't want to come home and find water all over the floor. Although they way it is piped that would be limited to only the top inch of water in the tank if it did occur.

The 100ââ"šÂ¬Ã¢"žÂ¢ of tubing was plenty of pressure drop with only a gravity feed to control flow. For the first 5 days the nitrates going in and out were the same. Then they went to zero . At this flow rate is is doing about a 50% daily water change, depending on who is doing the dilution math. I continue to feed dilute alcohol at the rate of about 100ml per day of 100 proof. Nitrates returning to the tank are zero.

When I receive the sulphur balls next week, I will change out the second stage carbon so I can stop feeding the system alcohol.

Testing responsiveness to high loading:

TEST:Yesterday I fed the tank extremely heavily. A half dozen frozen cubes and a lot of dry food. It was a snow storm of food. Everyone gorged themselves. Within 12 hours the nitrates rose to 10 ppm in the water column, zero discharged from the nitrate filter. No phosphate detectable. Within the next 12 hours nitrate were down to 5 ppm, zero discharged from filter. I expect nitrates to be gone within 48 hours. With heavier than normal daily feeding I do not feel nitrates will any longer be an issue.

I know at first glance this appears to be a lot of additional equipment and work. It isnââ"šÂ¬Ã¢"žÂ¢t and both processes 2 and 3 can run virtually unattended and without any control. They are ready to rapidly respond to widley varying loads. Believe it or not this all still fits in the base of my cabinet. Iââ"šÂ¬Ã¢"žÂ¢ll let everyone know how the sulphur balls perform in comparison. I am a little concerned about the sulphur by products, but from what Randy has published they should not be a problem.:rollface:

 

[Shoestring Reefer]

Do you have any concerns with the RowaPhos fluidized bed filter in the event of a power failure? One of your earlier posts had a link to a site that discussed how phosphate can be liberated from iron-rich substrates under anoxic or anerobic conditions-I forget which. Those conditions could be present in the fluidized bed filter during a power outage, and if the filter was to start up then a large amount of phosphate could be released from the filter.

Have you considered a safety system where the fluidized bed pump must be manually re-started after a power outage, or after a power outage of a minimum duration?

 

[ldrhawke]

Do you have any concerns with the RowaPhos fluidized bed filter in the event of a power failure? One of your earlier posts had a link to a site that discussed how phosphate can be liberated from iron-rich substrates under anoxic or anaerobic conditions-I forget which. Those conditions could be present in the fluidized bed filter during a power outage, and if the filter was to start up then a large amount of phosphate could be released from the filter.

Have you considered a safety system where the fluidized bed pump must be manually re-started after a power outage, or after a power outage of a minimum duration?

RowaPhos is probably being used my hundreds, if not thousands, of reef keepers in fluidized bed filters. I have never heard of that being a problem or concern. The literature states that phosphates are not released even if it is not removed, the Rowa phos product performance simply slows down.

I initially used RowaPhos in a bag. It quickly became like a brick, and was not very penetrable after a short while. I went to a fluidized bed to stop that from happening and improve performance. If you put too high a flow rate through the fluidized bed, the RowaPhos continues to put out fines and the water never stops being cloudy. The trick is a very low flow rate in the fluidized bed. It is amazingly affective when used properly.

That post you reference was referencing natural mud under highly anoxic conditions with pH's into the 6's, that caused phosphate release conditions. I doubt it is possible to get a cup of RowaPhos in a fluidized bed filter to simulate those conditions.

Your point may have some validity in the DSB itself as the the ferric dust given off when you first start up a new RowaPhos filter and the micro-fines seep into the DSB anoxic zones with the CPW wasting. It is possible that is in part why I no longer have any measurable traces of phosphate in my CPW drainage. The RowaPhos may cause phosphate to be released or the opposite, firmly bound in the DSB as CPW pulls it down into the bed. My bed does not appear to get pH's into the 6's, so I would guess the latter.

 

[ldrhawke]

typo correction

typo correction

Updating my CPW and CPW effluent polishing system testing experimentation.

......... I continue to feed dilute alcohol at the rate of about 100ml per day of 100 proof.

That is 10ml per day. Not 100 ml per day.