DSB Heresy

[Fredfish]

OK, so if I understand correctly, since you started this wasting, Your ORP has gone up, nitrates and phosphates have gone down, though this is also due to reduced feedings, algae growth has slowed/reduced.

Did you have any plans to increase your feeding back to previous levels to see what happens to your water parameters?

It is most interesting that the rotten egg smell is gone. I was wondering if you were draining enough liquid from the sand that it would have a permanent effect on the bacterial makup of the bed. It obviously does.

AK! Whenever I get involved with these discussions I end up with more questions than answers. Is there a relationship between nitrogen based reduction and sulfer based reduction? From my reading on coil denitrators, I got the impression there was; that sulfer based reduction started to happen once the nitrates had been completely reduced.

By the way, the link to the OZestuary site is broken. I couldn't find the page you were refering to. Interesting site though.

Continuous low rate drain back into the tank has been tried before with little success. The conventional commercial bottom filter with a bubbler does that.

True, but, in terms of nitrate reduction, the flow rate is critical. A conventional UGF probably has to high a flow rate to make the bed an effective de-nitrator. From what I understand, if the flow through the "denitrator" is to high, nitrogen reduction is incomplete, and you end up going backwards, converting nitrates back to nitrites.

The idea is to get the flow rate through the sandbed to the point where nitrates are completely reduced, but high enough that sulfer based reduction does not happen. That should mitigate ORP issues. It does not address nutrient export the way wasting does, but I plan to use an ATS style filter for nutrient exports.

I must say I find the idea of doing water changes using your system most compelling. Why not do water changes where they will do the most good?

It will be interesting to see how your system progresses over time.

Fred.

P.S. I am still interested in hearing what has changed withyour corals that leads you to conclude that they are more healthy.

 

[H20ENG]

Brett,
I dont think it was Tom Frakes, not 100% though. I need to dig out those articles.
ldrhawke,
I am curious that now you are not getting any H2S smell, that you may be overoxygenating the bed, thus turning it into a very slow UGF. Obviously you are testing the "liquor" (Oh yeah, I remember my wastewater days ), but how about DO levels?
Just thinking there may be too much of a good thing. At worst, it'll diminish the denitrators in the bed.
Forgive me if you are already on it, just thinking aloud
Chris

 

[ldrhawke]

Just thinking there may be too much of a good thing. At worst, it'll diminish the denitrators in the bed.
Forgive me if you are already on it, just thinking aloud

Can't have too much of a good thing if I am using the DSB mainly as a sink, and secondarily as a biological filter. I really don't care if denitrators diminish. When people stop trying to figure out how CPW is interfering with possible biological processing in the bed, they will have a better idea of what it is doing.

The concept of CPW is to maintain the aerobic processing in the upper area of the bed and also maintain a positive flow into the bed. I have not been measuring DO. It would be interesting but not a driving number.

The idea is to remove nitrates, phosphates, hydrogen sulfide and other organic waster that collects in the bed and also keep it from being released back into the tank. I am hoping it will improve the nitrification process by feeding it better and give it back the space that sulfate reduction is using up.

Accepting the fact that waste does accumulate in a DSB, it is also important to have adequate flow to remove it and not let sulfate reduction become dominate, which will stop the nitrification and denitrification that may be present. CPW will also help to assure that if the bed is disturbed what is release doesn't reap havoc and sudden death.

The reduction in rotten egg smell from wasting a quart a day is indication to me I am heading in the right direction.

What a lot of people are missing is the important of the physical method to accomplish this. It makes all the difference in the world as to the CPW process working well or not working. If you do not harness the natural behavior of fluids to follow the path of least as they are removed from a DSB, the chances of CPW working are greatly reduce. This is a major key success. I am applying some of the same hydraulic principles I have patented in composting.

Obviously over time and with more people using the concept we can start to narrow the band on the volume of the wasting and frequency. I would not be suprised if the volume of CPW increases, simply to assure of adding back trace elements in fresh salt mix. CPW may not be controlled by the minimim volume required to make a DSB a positive element in a reef tank and not the negative one that many people view it as now because of it's acting as waste collection sink that eventually boils over.

 

[H20ENG]

What about nitrate accumulation then, if the lower bed begins to lose its reducers? I believe that the "good" denitrification takes place without going as far as producing H2S. I understand your theory, but it seems you can do both- drain off the accumulated waste and do it slowly enough that the DSB can still denitrify.

 

[Shoestring Reefer]

ldrhawke-
One reefer has been using a DSB with plenum for 9 or 10 years successfully. I believe he is "aged salt". I don't know if he has flow through his plenum or not, but he may be worth talking to.

Also, you state (simplified) that using the plenum/DSB system and removing water from the plenum will help prevent phosphate from being removed; the widely believed problem with DSBs is phosphate buildup, and I have heard little about problems with H2S buildup (not that it doesn't happen, H2S just may be the cause, and reefers care about the phosphate). That's an interesting relationship, it may explain things.

 

[ldrhawke]

The major problem with trying to make any DSB affective in de-nitrification is the lack of volume in even a 6' bed. If you reduce the rate of fluids down to the point that it efficiently de-nitrifies, then the fluid throughput does produce enough volumetric turn over of the tank to keep nitrates from building up in the system.

De-nitrification is many times slower than nitrification. Yes you could build a large de-nitrification chamber to to accept the fluid wasted from the plenum....but why?

You go to all the trouble to recycle the water in the tank and add all sorts of fancy expense equipment only to then turn around and make water changes that exceed the amount you are wasting by using CPW. I hope to be able to eventually tune the wasting volume so that it totally eliminate the need for any water changes, above what is accomplished through CPW. It doesn't make any sense to complicate a simple process .

I maintain one key principle when I do process design work ....KISS. It is always the key to long term success. It is easy to complicate and an art to simplify.

 

[Fredfish]

The major problem with trying to make any DSB affective in de-nitrification is the lack of volume in even a 6' bed

I am not sure I agree with that. A clownfish breeder here on RC (rsman) manages nitrates in his breeding setup with a series of coil denitrators. Now, a sand bed, particularly if it has fine sand, should have a much higher effective surface area than a coil denitrator and so, should be more effective.

The concern I would have with "tuning" denitrification in a sandbed would be with channeling of water through the sand. I know nothing of fluid dynamocs, so don't know how water would flow through a sandbed in low volumes.

I agree with KISS. There are a lot of different ways to acomplish denitrification and nutrient export. I happen to like deep sand beds because of the fauna they produce. I also like the idea of gaining greater "value" out of all that surface area by using it in ohter ways. Wasting would be one way. turning it into a more effective denitrator would be another. Either one can be very simple.

Fred.

 

[BORECKI]

............. I would not be suprised if the volume of CPW increases, simply to assure of adding back trace elements in fresh salt mix. ........

Good thought!
One thing I'd like to add is this; You state that you remove a quart of water in about fifteen seconds every eight hours. In other words you "pulse" the DSB. Which is completly different from what others have tried in the past.
So far so good..
BUT
One quart of water divided by the floor area of your tank is probaly on the order of a few millimeter at most of water hieght. To have the water move through the sand such a small distance in fifteen seconds may not be enough to move solids through.
Another concern I have is with the filter cloth possably cloging with solids over time. Would you concider doing one three quart pulse in stead of three seperate quart pulses in the same time frame? And is it possable to speed up the water flow during the pulse to helpe dislodge some of the 'pasty' solids during the process?
Boris.

 

[ldrhawke]

I am not sure I agree with that. A clownfish breeder here on RC (rsman) manages nitrates in his breeding setup with a series of coil denitrators. Now, a sand bed, particularly if it has fine sand, should have a much higher effective surface area than a coil denitrator and so, should be more effective.

The concern I would have with "tuning" denitrification in a sandbed would be with channeling of water through the sand. I know nothing of fluid dynamocs, so don't know how water would flow through a sandbed in low volumes.

I am nit sure that I follow your or that you understand what I have said.

De-nitirifcation does and will take place in a CPW DSB. It is just not adequate to handle the load. You will still have nitrates in the wasted fluid. So what. They are dumped in the drain.

Yes, you can denitrify in a coil or fluidized bed. It would cost to build and operate either of the size required. Why would you build a denitrification if you did not need to? You do not have to with CPW.

The gallonage of a denitrification is very close to the gallonage of your tank. It also should be a batch system, two systems in parallel, to be affect. This is what is used in municipal and industrial WWTP's.

Also, picture the problem of continuely recycling denitrified water back into the tank from a denitrification system!

I'll ask you with an analogy.

If you added a red dye to the water in your reef tank. The red dye representing nitrates. Then you slowly fed into the tank a whole tank of clear pure water, allowing the excess to over flow, how many complete tank changes do you think it would take before you had no trace of pink in the water? Because you do not have a plug flow, but a complete mix exchange, I'd guess 50 to 100 tanks.

Now you know why is is simpler and more positive to dump the concentrated plenum waste to drain.

 

[ldrhawke]

I am not sure I agree with that. A clownfish breeder here on RC (rsman) manages nitrates in his breeding setup with a series of coil denitrators. Now, a sand bed, particularly if it has fine sand, should have a much higher effective surface area than a coil denitrator and so, should be more effective.

The concern I would have with "tuning" denitrification in a sandbed would be with channeling of water through the sand. I know nothing of fluid dynamocs, so don't know how water would flow through a sandbed in low volumes.

I am not sure that I follow your statements or that you understand what I have said.

De-nitirifcation does and will take place in a CPW DSB. It is just not adequate to handle the load. You will still have nitrates in the wasted fluid. So what. They are dumped in the drain.

Yes, you can denitrify in a coil or fluidized bed. It would cost to build and operate either of the size required. Why would you build a denitrification if you did not need to? You do not have to with CPW.

The gallonage of a denitrification is very close to the gallonage of your tank. It also should be a batch system, two systems in parallel, to be affect. This is what is used in municipal and industrial WWTP's.

Also, picture the problem of continuely recycling denitrified water back into the tank from a denitrification system!

I'll ask you with an analogy.

If you added a red dye to the water in your reef tank. The red dye representing nitrates. Then you slowly fed into the tank a whole tank of clear pure water, allowing the excess to over flow, how many complete tank changes do you think it would take before you had no trace of pink in the water? Because you do not have a plug flow, but a complete mix exchange, I'd guess 50 to 100 tanks.

Now you know why is is simpler and more positive to dump the concentrated plenum waste to drain.

 

[ldrhawke]

sorry for posting twice ...tried to correct for my dyslexia.

Let me also add. Also, if you try to recycle waste and use denitrification, it may remove nitrates but it does not address the phosphate and other types of waste you may be also recycling.

 

[ldrhawke]

BUT
One quart of water divided by the floor area of your tank is probably on the order of a few millimeter at most of water height. To have the water move through the sand such a small distance in fifteen seconds may not be enough to move solids through.
Another concern I have is with the filter cloth possibly clogging with solids over time. Would you consider doing one three quart pulse in stead of three separate quart pulses in the same time frame? And is it possible to speed up the water flow during the pulse to help dislodge some of the 'pasty' solids during the process?
Boris.

I will be the first to state, I don't know how much of a wasting is needed. I am sure that as reefers get aboard and start to use CPW, everyone will all have a slightly different approach.

The nice thing about the CPW, the way I have set it up, is everyone is free and able to tune it in to meet their own needs. No two tanks size or need is the same. Size, organic loading, etc, etc are all different.

If you follow my recommendations for constructing the plenum, clogging and blinding will not be a problem. You are only removing a small controlled quantity over a large surface area.

There are no solids removed, the bacteria has eaten or dissolved them by the time they reach the plenum. You are removing a solution.

I no longer have any sign of detritus on the bottom of my tank.

Keep in mind what we are going from to. A conventional DSB without CPW is a dead end garbage can. Even though many DSB system have gone belly up in a couple of years. Some of these system, if lightly loaded have lasted for years.

With CPW you now have a positive movment and transfer in your DSB. It isn't going to take much transfer to make a significant positive change to the DSB concept. In fact you may not want anything but a very low flow to make it maintain the highest oxic processing rates.

 

[Shoestring Reefer]

The major problem with trying to make any DSB affective in de-nitrification is the lack of volume in even a 6' bed.

A significant number of hobbyists will testify that DSBs have reduced there nitrates to zero, even in 6" beds. DSBs are good denitrators. Their issue is longevity, not capacity to denitrate.

The major problem with trying to make any DSB affective in de-nitrification is the lack of volume in even a 6' bed. If you reduce the rate of fluids down to the point that it efficiently de-nitrifies, then the fluid throughput does produce enough volumetric turn over of the tank to keep nitrates from building up in the system.

I think what you are saying is that by introducing flow through the bed, you compensate for the lack of volume. Correct me if this is an incorrect interpretation.

De-nitrification is many times slower than nitrification. Yes you could build a large de-nitrification chamber to to accept the fluid wasted from the plenum....but why?

Because:
-It has been used successfully in at least one aquarium for about a decade
-It requires no moving parts
-Its abilities and limitations are well understood
-It has ben studied long-term

You go to all the trouble to recycle the water in the tank and add all sorts of fancy expense equipment only to then turn around and make water changes that exceed the amount you are wasting by using CPW. I hope to be able to eventually tune the wasting volume so that it totally eliminate the need for any water changes, above what is accomplished through CPW. It doesn't make any sense to complicate a simple process.

Compared to the DSB with plenum, you have added significant complication.

I maintain one key principle when I do process design work ....KISS. It is always the key to long term success. It is easy to complicate and an art to simplify.

You presented a non-traditional DSB method with short-term success and claim it has significant advantage over traditional DSBs. I suggested you speak with someone with long-term success with another non-traditional DSB. Your response to that was dismissive. Based on your posts here and otherwhere on this forum, I get the impression you are promoting an idea in order to get recognition, rather than helping discover the truth. It is discouraging to see someone focus so much time and energy trying to convince people of the long-term viability of something with only short term success. DSBs also have the same short-term success; your method does not seem to provide no additional benefits. At this point, you have presented no basis for the claims that it is better than a DSB. You have theories, but so do many other people.

What is the risk in using CPW? Zero!

What is the potential upside.....

I like those type of odds....

I like the odds, where's the proof. I believe stating that your alternate DSB method has zero risk is not justified until there have been many hobbyists with many years of success.

 

[ldrhawke]

You presented a non-traditional DSB method with short-term success and claim it has significant advantage over traditional DSBs. I suggested you speak with someone with long-term success with another non-traditional DSB. Your response to that was dismissive. Based on your posts here and otherwhere on this forum, I get the impression you are promoting an idea in order to get recognition, rather than helping discover the truth. It is discouraging to see someone focus so much time and energy trying to convince people of the long-term viability of something with only short term success. DSBs also have the same short-term success; your method does not seem to provide no additional benefits. At this point, you have presented no basis for the claims that it is better than a DSB. You have theories, but so do many other people.


quote:
Originally posted by ldrhawke

What is the risk in using CPW? Zero!

What is the potential upside.....

I like those type of odds....


I like the odds, where's the proof. I believe stating that your alternate DSB method has zero risk is not justified until there have been many hobbyists with many years of success.

No problem.....I really haven't follwed any of the logic of your comments, other than some sort of animosity......in 15 years give it a try.... or not.

Happy New Year

 

[BORECKI]

For now I am intrigued with the concept and am willing to try it in a future tank.
Mind you I came from growing Koi for sale (doing 50% water changes / week) to my current DSB. I started reefing with a BB (berlin sistem)and doing 25% water changes, killing fish & corals in the process. And thinking something is wrong with the concept. Till I found out about DSB's.
My current incarnation is a 65 show tank with 4.5 square feet of floor/DSB @4inches coupled to a 33long refugium/DSB (12X13X48) with another 4 square feet of floor/DSB @ 6 inches with linier flow across the lenth of the refugium (coral rubble above the sand.
Total DSB of 8.5 square feet and NO water changes in three years! Another note; the first time I got corals to grow & reproduce instead of dieing was after I want DSB.
About a year ago my A. clarke maited pair got fiesty with my other fishes and I banished them to the refugium (along with their BTA host. Mind you the free water hight in this tank is only 6 inches. So the first thing they did was to make more room for themselves by diging into the DSB a crater and moving the excess sand down stream.
They disturbed a square foot of sand down to the bottom.
Nothing happned!
No roten egg smell, no die off, nothing.
Having said that; lets say I'm a fan of DSB's in tearms of ease of maintenence, lower water changes, stabilaty, etc.
But what's being put forth out here is a good idea and I really don't see how it can hurt to try.
Until further info comes out, one thing I WON'T do is go back to bare bottomed berlin sistems.

 

[ldrhawke]

For now I am intrigued with the concept and am willing to try it in a future tank.
.................They disturbed a square foot of sand down to the bottom.
Nothing happened!
No rotten egg smell, no die off, nothing.
Having said that; lets say I'm a fan of DSB's in tearms of ease of maintenence, lower water changes, stabilaty, etc.
But what's being put forth out here is a good idea and I really don't see how it can hurt to try.
Until further info comes out, one thing I WON'T do is go back to bare bottomed berlin sistems.

When you get around to setting it up drop me a note and I'll try to help. Designing the plenum piping to get a more uniform flow through the substrate is important.

I am not surprise that you didn't get a rotten egg smell as the fish dug down. If any hydrogen sulfide was present it was being released slowly.

The more I experiment with CPW,the more I am convinced that sulfide reduction plays a bigger role in tank biological unbalance and shock than a lot of people think. It is easy to have are relatively large dead zones in a convention DSB where sulfide reduction can take over. If sulfide reduction takes over in the DSB and it becomes dominant, like a lot of reefer describe when digging a few inches into a bed and find a large black or gray zone, the fluid in this zone will cause a tremendous shock to the life in the tank if released quickly.

Try this experiment to get a better understanding of why I believe this. If you have a few feet of syphon hose around, drain a little of your tank water off the bottom, to fill it. Cap off the hose and allow the water to sit for a week before draining it into a glass. Smell the water.

You are never going to stop sulfide reduction in a DSB. It will always have dead zones, But, by using the Controlled Plenum Wasting (CPW) built as I describe, you will significantly reduce the amount of sulfide reduction across the DSB.

I feel this will opens up these dead zones and may allow the DSB to become more productive in both oxic nitrification and anoxic dentrification, making for even more productive DSB processing by slowing down sulfide reduction and also feeding the bed with positive flow and new fluid from above.

What is the basis of this premise? Right now I have very little rotten egg odor from my plenum wasting fluid. When I started CPW the odor in the wasted fluid would knock your socks off.

The first concern many reefers have when I describe this is that it will stop denitrfication, because of some more oxic fluid will move into the anoxic zone. I don't believe this stops denitrification based on my long term commercial experience in a very similar set of conditions when processing organic waste.

A DSB is not uniform with oxic and anoxic bacteria sitting in nice uniform layers. It has many many non-uniform zones in a continuous state of flux, moving from an anoxic state to oxic state and reversing depending on available food and oxygen. It is not this nice uniform layer of oxic processing the first 2 inches down and then all anoxic to the bottom often described by reef experts.

This is why many reefers find black sulfide reduction substrate just below the surface. But his is a whole new topic.

 

[ldrhawke]

For those Reefers from Missouri

For those Reefers from Missouri

Based on your posts here and otherwhere on this forum, I get the impression you are promoting an idea in order to get recognition, rather than helping discover the truth. It is discouraging to see someone focus so much time and energy trying to convince people of the long-term viability of something with only short term success. DSBs also have the same short-term success; your method does not seem to provide no additional benefits. At this point, you have presented no basis for the claims that it is better than a DSB. You have theories, but so do many other people.

For those reefers who read my ideas about CPW and feel the way "Shoestring Reefer" does, I have no need to blow my own whistle. I am simply passing on a concept that I believe has merit and potential.

I am new in reef keeping, but not new to biologically stabilizing detritus. I have been designing and building commercial waste treatment facilities for over 30 years. A single one of my processing facilities biologically stabilizes more human and animal detritus in five minutes than all of the RC reefer keepers and their tanks could produce in a life time. The treatment demands and obstacles are very similar.

I have added my company Website to my profile. Hopefully it will dampen insults.

 

[Shoestring Reefer]

I really haven't follwed any of the logic of your comments

Ok, I felt that each of my comments specifically addressed the quote it followed. If there is any specific comment or question you would like clarified, feel free to ask.

 

[Shoestring Reefer]

Significant IRON in DSBs?

Significant IRON in DSBs?

I will try bo be specific and clear with this post.

(Eq. 3) 106(CH 2O)16(NH 3)(H 3PO 4) + 53SO 42- ââ"šÂ¬Ã…"œ106 CO 2+ 16 NH 3+ H 3PO 4+
106 H 2O + 53 S 2- Iron sulfides ( e.g . pyrite), formed during sulfate
reduction, are an active component of acid sulfate soils (***),
and problems with acid production and drainage can arise if the pyrite
is oxidised .

Iron sulfides cannot bind phosphate . Therefore, when iron oxyhydroxides are converted to iron sulfides during sulfate reduction, phosphate can be released to the water column [9].
______________________________________________________________

The above leaves little doubt in my mind as to why a conventional DSB is a crap shoot and a ticking bomb. I will continue to run my experiment with removing this sulfide rich waste soup to see if a DSB can be made to work. Without a method of removing all of this bad soup from the bottom of any DSB I don't believe they can* work. *(can is relative. I mean eventually fail)

The logic presented above seems to suggest that phosphate is released because "when iron oxyhydroxides are converted to iron sulfides during sulfate reduction, phosphate can be released to the water column". Do you beleave DSBs have enough iron for this to be significant.

Are you suggesting that there can be enough iron in the DSB to be significant in terms of phosphate retention and release, yet low enough to not kill every invertibrate in the tank?

To be clear, let me phrase it another way: how much IRON do you beleave is in people's DSB.

 

[ldrhawke]

My wife is NOT impressed with how much I spent on Fighting Conch

Shoe String,

If your think your wife was not impressed with your Fighting Conch, trust me....I am even less impressed with what you consider to be an apology.

You are on my IGNORE LIST. I do not want to spend the time and energy trying to convince you of anything.