DIY Coil Denitrator Plans

[rsman]

here is a start ill come back later to answer more


I've been through the thread again,
kewl big post I am not going to reread this thread or search for all the denitrator threads or anything like that, but if someone were! maybe this this stuff might not need to be restated ??? wanna volunteer??? also i cut out some of the repetitive stuff.

and I can't understand why the coil can be too long or why there can be too much media in the chamber -- in other words, how can a denitrator be too big? your not building a denitrator thats too big, your building one thats off sized, its like taking a 6' tall 12" diameter skimmer and powering it with a rio-600 and complaining that "i have a huge skimmer" and "it isnt working" however yes you can have one thats too big, ill see if i can explain better in the following

This is how I see it, and you can correct me so I understand. If there's something I should read, maybe you could point me in that direction. Please bear with me. I have no problems responding but understand the "breeder on vacation" is serious I no longer work with fish, i keep 2 tanks! so when I have to look thru things it just takes me longer to respond, but im more than happy to respond. for reference there are other denitrator threads id suggest the breeding forum first as thats where i was usually hanging but .... better places to look for information on these if your so inclined (crazy) is the university libraries in the waste management stuff, these were a way of dealing with nitrate on a seriously HUGE scale compared to what were doing.

1. The coil tube receives water rich in O2 from the pump. dont forget gravity can work for these smaller units
2. As bacteria colonise the tube, you have aerobics oxidising the organics and producing ammonia, nitrate and nitrate.yes but as long as there is nitrite and ammonia denitrification is slowed even paused
3. The slow progress of the water ensures maximum contact time.this is NOT a slow process, water flow along the surface of your coil should be moving FAST!!! the length allows the water at the center of the coil to equlize with the water on the surface of the coil, a smaller diameter coil would need a significantly shorter length, but would be more prone to cloging, and at the other end a larger diameter coil needs a significantly longer length
4. The aerobics will colonise as far along the tube as oxygen lasts. with luck the aerobic bacteria will colonise the entire tube, but for the most part, the problem is that length is not fixed, it changes as your tank changes
5. When oxygen runs out, anaerobes start colonising the inside of the tube. start yes but not fully colonise the anerobic bacteria dont like the high flow rates, they are not as ?sticky? and anerobic respiration takes more time, and effort and the start of the anoxic zone in the tube changes rapidly and frequently, this creates a middle wasted area one reason those w/o the chamber need significantly longer runs or much lower flow in a perfect world the end of that wasted area would be the end of the coil!
6. So part of the tube will be aerobic and part anaerobic.if the tube maintians an anoxic zone you will have more problems than not. see #5. the job of a coil in a coil denitrator with a bio chamber is to remove the oxygen only, this creates a stable filter
8. When the water leaves the bottom of the coil, it passes through the media in the chamber with a reduced amount of nitrate. actually an increased amount of nitrate there was a high cost to supplying the coil which consumed the oxygen, that cost is more nitrate. one reason some people will see an increased nitrate level out of the coil durring cycling.
9. Whatever nitrate is left is then processed by the anaerobes living on the media. and as long as there is nitrate in the anoxic water there will be denitrification and no penilty, once you have used the nitrate more media means bacteria need to consume something else and thats bad


If the chamber contains (say) one quart of media, the anaerobes here will process whatever nitrate is available. and then what something has to happen next.... the possible results are 1. an unstable denitrator 2. hydrogen sulfate gas because the bacteria ate something other than nitrate 3. a denitrifier that doesnt remove as much nitrate as it adds.


If you double or triple the amount of media, you are still treating the same amount of nitrate. true a fully functioning unit will have 0 nitrate in the output regardless of the nitrate level on the input

BUT

The same number of bacteria will be present false nitrate is not the only thing these bacteria can process, nitrate is what we want them processing

only enough bacteria will form according to the amount of nutrient nitrate isnt used in this process as food, and they can use things in the water other than nitrate, things we cant/dont want to remove.

I can understand that having a coil longer than necessary and more media than needed may be a waste of materials,
the cost of material is so low that i never even think of it

That's why I planned to build a denitrator bigger than I really need -- a bit like having a skimmer bigger than needed in case something goes wrong, or having an extra heater in the tank in case of extra-cold weather or a failure of a heater. if you want bigger have more coils not a longer coil or larger chamber.

Sorry for rambling on so much, but I needed to explain how I think (which is probably simplistic). You seem to be very knowledgable and I've no doubt you've got good reasons for your comments. I'm not challenging what you say. I'm the kind of person who likes to know why I'm doing what I'm doing.i dont mind rambling and its not an uncommon line of thinking its just wrong .... I really did drop out of fish keeping i have 1 planted FW tank and 1 almost a reef, both have coil denitrators but neither have been getting much attention so its probibly safer to say i was knowledgable im just too busy/lazy to remove myself from RC so i get reminders, PM's and emails .... I didnt preceve it as a challange but if you know something ive forgotten have at it if you want, but it wont be much fun, ive forgoten more than i ever wanted to know about these.

[s a v v o]

Thanks for your detailed reply.

Les

[rsman]

as for no change i ment there is not nitrites and no ammonia, but still 40ppm (same as tank) of nitrates comming from it. haven't checked the pH comming from it yet. the flow comming out of the tubing is a fast drip just slower than a stream but still a drip. you might wanna post what you have done, but it sounds way to fast of a flow to me.

i also don't understand why the coil can be too long or why there can be too much media in the chamber -- in other words, how can a denitrator be too big? in case i didnt clear it up, its not bigger, bigger would be larger everything not just more media or longer coils.

why would i get the possibility of low but varrying nitrate levels and not completly all 0? the extra media can create more nitrate and some nitrite(easilly processed by tank filtration) than the entire unit consumes at times.. creating a varrying nitrate level, and the difficulty keeping the flow right will cause the non 0 levels. this doesnt need to be taken any further than that, it doesnt need rebuilding itll work, but as b4 longer cycle, varrying nitrate levels, and non 0 numbers. NOT a big deal!!!

i don't know what else to do make sure your cycling it correctly, then WAIT

[s a v v o]

rsman, now you've REALLY got me confused!

I wrote: The slow progress of the water ensures maximum contact time.

You wrote: this is NOT a slow process, water flow along the surface of your coil should be moving FAST!!!

Sam wrote: the flow comming out of the tubing is a fast drip just slower than a stream but still a drip.

You wrote: It sounds way to fast of a flow to me.

Would you mind explaining this, please?

Thanks.

Les

[32flavors]

i also don't understand why the coil can be too long or why there can be too much media in the chamber -- in other words, how can a denitrator be too big? in case i didnt clear it up, its not bigger, bigger would be larger everything not just more media or longer coils.

Okay, so if the coil being longer (and why is that bad) and there's more media (which implies a larger / bigger unit in order to facilitate the increased capacity) what WOULD make the thing BIGGER?

I mean, most of use larger capaity units than we need to increase processing, etc... so why is an overall larger unit not better?

What size / configuration unit would you recommend for a 300 gallon system?

Also, how do you get nitrite and nitrate production in a zero oxygen environment?

Sorry.... I'm just confused.

[rsman]

rsman, now you've REALLY got me confused! nothing new there


I wrote: The slow progress of the water ensures maximum contact time.

You wrote: this is NOT a slow process, water flow along the surface of your coil should be moving FAST!!!

Sam wrote: the flow comming out of the tubing is a fast drip just slower than a stream but still a drip.

You wrote: It sounds way to fast of a flow to me.

Would you mind explaining this, please?
its actually very simple

when i was responding to you, i was responding to a specific question about how the coil portion of the unit works, water flow across the surface of the coil needs to be fast, in contrast water flow across the media in the bio chamber needs to be slow.

but

when i was responding to sam, he has a cycling unit, when you start these off you have to start with a very slow flow and build up to a faster flow, he is not there yet. (i dont think he needs to adjust, test, respond to be sure)

[rsman]

Okay, so if the coil being longer (and why is that bad) and there's more media (which implies a larger / bigger unit in order to facilitate the increased capacity) what WOULD make the thing BIGGER?

I mean, most of use larger capaity units than we need to increase processing, etc... so why is an overall larger unit not better?

I think ive answered this a few different ways now, but lets try another, you cant buy a stock ford ranger, and only put a bumper on it that will tow a 60,000lb trailer and say the ranger can pull a 60,000lb trailer that puny engine wont do it, the breaks wont do it, the transmition wont do it, it just wont work.

no one here in the last 3 pages has suggested building an overall larger unit, they keep thinking that extending the coil length alone is somehow better, ITS NOT also they keep making these huge bio chambers as if thats going to make it process more... it WONT a properly working and cycled unit removes all nitrate AFTER giving to any abrupt changes this is still a bio filter increasing the size of 1 part isnt going to make it better.

What size / configuration unit would you recommend for a 300 gallon system? kinda depends on the load, but you have choices, increase the ENTIRE size of the coil (not easy to do) or add more coils, for anything but HIGH bio load the easiest approach is to just add 2 or 3 coils to the same units. i know there is a simple table somewhere but 1/4"OD icemaker tubing is good between something like 50 and 75 feet, but 1/2"ID tubing needs to be over 250 feet to be opened up to anything making 1/2" tubing worth it and that is a LOT of tubing and a HIGH flow more than 300gph (for reference there is cheap 1/2" irrigation tubing available and its what ive used on breeding setups)

Also, how do you get nitrite and nitrate production in a zero oxygen environment? chemically ask a chemist i dont wanna dig thru papers to pull out the stuff. nitrate is produced in the coils as the oxygen is removed this is normal, however also normal is that the bio chamber has built up enought to process nitrate the increase from the coil is completely consumed. the nitrite is produced in 2 places normally in the coil, as those things that breethe oxygen are at work it can get thru the unit while cycling, and in the bio chamber when the bacteria in the chamber die.

Sorry.... I'm just confused. if your still confused please speak up

[s a v v o]

OK, thanks, rsman.

I wrote . . . The slow progress of the water ensures maximum contact time.

You wrote . . . this is NOT a slow process, water flow along the surface of your coil should be moving FAST!!!

Later you wrote . . . When i was responding to you, i was responding to a specific question about how the coil portion of the unit works, water flow across the surface of the coil needs to be fast, in contrast water flow across the media in the bio chamber needs to be slow.

Sam wrote . . . the flow comming out of the tubing is a fast drip just slower than a stream but still a drip.

You wrote . . . It sounds way to fast of a flow to me.

You then wrote . . . When i was responding to sam, he has a cycling unit, when you start these off you have to start with a very slow flow and build up to a faster flow, he is not there yet. (i dont think he needs to adjust, test, respond to be sure)

So we’ve got these statements from you . . . water flow along the surface of your coil should be moving fast . . . water flow across the surface of the coil needs to be fast . . . when you start these off you have to start with a very slow flow and build up to a faster flow.

From what you said to Sam about his being too fast, it seems to mean when I start up the system to cycle it, it needs to be ‘slow’ and then when the system has finished cycling I need to increase the flow to ‘fast’.

Can we define ‘SLOW’ and ‘FAST’? They mean different things to different people. Let’s base it on your suggested size: a coil of 50 feet, ¼-inch OD, a chamber 14 inches long and two inches in diameter.

To start the system off, would ‘SLOW' mean one drop per second, or one drop every two seconds, or whatever?
Sam’s rate is ‘A FAST DRIP, JUST SLOWER THAN A STREAM, BUT STILL A DRIP’. Is that FAST enough when the system is cycled and fully functioning?

Thanks.

Les

[rsman]

I really shouldnt be responding late at night, but life is worth living dangerously

I am fairly sure cycling is covered in this thread ill check tomorrow

So we’ve got these statements from you . . . water flow along the surface of your coil should be moving fast . . . water flow across the surface of the coil needs to be fast . . . when you start these off you have to start with a very slow flow and build up to a faster flow. yea flow thru coil needs to be fast more importantly when designing your unit it needs to be designed so it can be moving fast.

From what you said to Sam about his being too fast, it seems to mean when I start up the system to cycle it, it needs to be ‘slow’ and then when the system has finished cycling I need to increase the flow to ‘fast’. this is also correct, and cautiously as i dont wanna overly complicate it for anyone i think there was some findings that if you ran it full open for a few days to get all the air out and start getting bacteria started you *might* get a faster cycle, either way they were talking a few days, if memory serves you might find that in this thread or in one of the links. BUT cycling needs slower flow.

Can we define ‘SLOW’ and ‘FAST’? They mean different things to different people. Let’s base it on your suggested size lets not confuse this, sams unit isnt my suggested size, and im not suggesting a size as much as a ratio of coil diameter, length and bio chamber size, given the tank size posted. and 'SLOW' and 'FAST' have been defined they are defined by sam saying he has no ammonia, no nitrite and nitrate levels identical to the tank, if the water was slow enough durring cycling he should be seeing at least some nitrite(sam i hope your a HE) the size of the coil has no impact here, even that he built it too long, at this step he should be seeing nitrite, you get nitrite by slowing it down. there by its going to fast. this speed is just like cycling a fish tank, if it takes me 3 weeks and you 6 does that mean you did something wrong? usually not, this is a bio filter, it has to cycle.

To start the system off, would ‘SLOW' mean one drop per second, or one drop every two seconds, or whatever? there was a commercial unit available (i think it still is) that used the 50' 1/4"OD tubing its directions called for aprox 1/4 cup per minute either way get it going slow and TEST it

Sam’s rate is ‘A FAST DRIP, JUST SLOWER THAN A STREAM, BUT STILL A DRIP’. Is that FAST enough when the system is cycled and fully functioning? no when sam's is cycled it should be going fast remember its a long coil.... and sam is going to have to make up for it. a 1/4"OD 50' coil should have a very steady stream in the output nothing you could consider slower than a stream it shoots out aprox 6~8" out of a horizontal tube as for how fast on sams id have to dig up stuff and think, clearly thats not going to happen tonight!!!

[s a v v o]

Thanks for taking all this time and effort to respond to my inquiries.

Best regards.

Les

[kau_cinta_ku]

ok so what if i just shrunk mine down to 14" or so and run only 50' of tubing but still leave the 4" diameter PVC would that work better or do I have to go to 2" PVC

thanks so much for all your help.

[rsman]

ok so what if i just shrunk mine down to 14" or so and run only 50' of tubing but still leave the 4" diameter PVC would that work better or do I have to go to 2" PVC

Im sorry this part of this thread is actually 2 seperate parts here, you have one working, and les is designing one

I thought i made it clear, I wouldnt change what you have. its not worth the little effort it would take, and all you would have to do is cut your coil in half ish. w/o cutting down the chamber id go for the 60' instead of 50' but either way i still wouldnt take the time. plus any length of cycling would probibly be offset as your already 2 weeks in, and you would have to start over completely

you have 100g of water you will get a nice turnover with this unit

the longer coil is a little bit of a pain, and it means that the denitrator is going to run differently, but you still have to test just like everyone else. you used bio balls not gravel/rock so you wont get any stagnent areas in the bio chamber IF you are going to build one again, dont build it that way, having a higher flow isnt bad, and 'slow' and 'fast' are still based on the test kits

[rsman]

Sorry you got missed if i do it agian yell at me

Originally posted by cpl40475
OK ive been reading this and seriously thinking about building one. My tank is a 75 gallon close to 90lbs live rock
a few diff types sps and lps corals 3 false percula clowns 2 3 stipe damsel and a yellowtail damsel. A D&D typhoon skimmer (im about ready to trash). 3 200gph powerheads and a emporer 400 hob filter. will the denitrator you described on page one work well with my system and what size pump do i need to put inline and what be be my best spot to have the water return into the tank at the emporer440?

its never best to put the output straight into another bio filter, a skimmer yes, but even better is someplace out of water where it can freefall into the tank or ?sump? if you have one, assuming you dont. these units dont work magic, and are not self cleaning of clogs letting it freefall means you will notice if it clogs, and blows off co2

any single coil unit will work nicely on a 75g tank, and you can T off any of those 200gph pumps nicely use the long leg of the T as the output and either end as the pump/coil will give a good push.

[rsman]

IN my defence for this mishap Id like to note I did mention that I havent been doing this lately, and its cearly on the first page of this thread

I missed a very important reason not to go insane building a bio chamber thats huge. building one just large enough means you have some extra space in the event of a clog or power failure. if water stops you get hydrogen sulfate and that will do very bad things to your tank, especially if that tank is already hurting from an extended power failure. I still feel Sam is OK without cutting down his unit, but this is another reason you dont want to be expanding on the size of things without a CLEAR understanding of whats going on. this is something I knew! and have forgoten!

hope this doesnt overly complicate anything

[32flavors]

Last quest, hopefully... On the first page you mention a couple of things...

1.) Having the effluent drip back into the sump--rather than the return being under water--prevents hydrogen sulfate? If not, what bad thing are you preventing (assuming the purpose for this also has to do with back flow in even of power failure)?

2.) If you use smaller diam tubing, then you need a shorter run--am I understanding that correctly?

3.) Your model for your 125 FOWLR tank is perfect for me.... would you do anything differently on it if you could, in terms of specs?

4.) For a 30 gal sheavily stocked ystem, what size chamber, tubing diam and run would you recommend?

5.) How long after initial TANK set-up do you recommend installation of one of these, or does it matter at all?

6.) What's the best way to tap/drain any gas build up in the top of the chamber--another hole with a ball valve?

Along with everyone else, THANKS AGAIN for all your patience and continued input!!

Cheree

[32flavors]

Sorry, couple more questions....

7.) On your 3-line unit, is the overall flow (after cycling) faster since you have 3 inputs, the same as if there were 1 or.....?

8.) What is the target effluent rate after cycling (yes, I know testing will determine exact final rate, but perhaps a place to start)?

9.) Does efluent need to be dripped over carbon, as with sulfur denitrators (yes, I know I'll probably take a hit for that one, but better safe than sorry right)?

Thanks Again!!!!!!

[willhoward]

I'm gonna come with a whole different question:
I understand the concept, the theories, the fast flow through the coils, the slow flow through the bio materia, and even the "bigger isn't necessarily better".

But what I DON'T understand is how you can design it to have a fast flow-in rate, and a slow flow-out rate? This is a sealed unit right? So if you put say 100gph flow rate into the unit, it seems logic to me that you will get an output flow rate of 100gph out of the unit? Did I miss something along the line?

[32flavors]

Excellent question

[rsman]

But what I DON'T understand is how you can design it to have a fast flow-in rate, and a slow flow-out rate?
you cant!

the flow-out rate is identical to the flow in rate

This is a sealed unit right? So if you put say 100gph flow rate into the unit, it seems logic to me that you will get an output flow rate of 100gph out of the unit? Did I miss something along the line?

yep u missed something

think of 2 wheels going the same 60mph down the road, if one is 8" diameter its going to be spinning faster (1267 rpm ) and the other if it is 40" it will be spinning slower (50 rpm) the rpm part asssumes im doing the math right but ....

the volume of the coil is only a fraction of the volume of the unit water flows the same rate thru the entire unit, it flows faster thru the coils and slower thru the bio chamber.


LMK if you didnt get that!!!

[rsman]

Last quest, hopefully... On the first page you mention a couple of things...
keep asking, otherwise ill forget everything, who am I?

1.) Having the effluent drip back into the sump--rather than the return being under water--prevents hydrogen sulfate? If not, what bad thing are you preventing (assuming the purpose for this also has to do with back flow in even of power failure)?
i think you got that wrong, or sorta. having it out of the water does not directly prevent hydrogen sulfate, except that it causes you to notice the unit is functioning, and when it stops (clogs or whatever) you will notice. it also does help to add oxygen and blow off gasses.

2.) If you use smaller diam tubing, then you need a shorter run--am I understanding that correctly? there is a point of no return, and too small clogs easily been there done that .... its not fun to be decloging these daily because you had to build the smallest unit you could for a 7gal allglass bowfront. however YES

3.) Your model for your 125 FOWLR tank is perfect for me.... would you do anything differently on it if you could, in terms of specs? its been over a year sense i touched it last, so id say nope wouldnt change a thing.

4.) For a 30 gal sheavily stocked ystem, what size chamber, tubing diam and run would you recommend? if its way way heavily stocked you know like 400 clown fish, then add 1 or 2 coils to the 50' units.

5.) How long after initial TANK set-up do you recommend installation of one of these, or does it matter at all? if you dont have nitrate it wont cycle but you can set it up right away, and it will cycle once you do have nitrate, there is no harm running them early, and it will partially cycle as your tank does.

6.) What's the best way to tap/drain any gas build up in the top of the chamber--another hole with a ball valve? best is just to ignore it. the output should be high up in the chamber and thats good enough.

7.) On your 3-line unit, is the overall flow (after cycling) faster since you have 3 inputs, the same as if there were 1 or.....? each coil will output aprox the same amount on the same fish tank, the entire units output is the sum of the 3 coils and each coil adds to the amount processed per hour. more coils = bigger UNIT

8.) What is the target effluent rate after cycling (yes, I know testing will determine exact final rate, but perhaps a place to start)? 2~8gph per 1/4"OD 50' long coil +/- depends on how its hooked up also bigger coil = higher flow rate, pumped input = higher flow rate ....

9.) Does efluent need to be dripped over carbon, as with sulfur denitrators (yes, I know I'll probably take a hit for that one, but better safe than sorry right)? doesnt need to be, i cant recall any reasons specifically NOT to.

[ReefKeeper69!]

Slightly off-topic... Sulphur-based (LSM) Denitrator...

I had long thought I might like to build a coil denitrator, but the current method under research is using an anaeorbic bacteria colonizing a sulfur-based media... CaribSea's LSM. Since the output is somewhat acidic, that is followed up by an arrogonite media chamber. This forms the basis a nitrate reactor, to consume nitrates in a similar fashion to the coil denitrator, and add CA as well. Still need to add buffer, but it may offer higher capacity than the traditional coil denitrator.

I haven't seen too many designs for these devices yet, but it's essentially a ganged fluidized bed, or slow-flow media chambers in series with one another... LSM feeds the aragonite chamber. You could use a pair of phophate reactors, potentially, to get the job done. This appeals to me more than the coil denitrator method...

Just thought I'd stir the sump some!

[willhoward]

Thanx rsman, that what I thought too, just wanted to make sure

[hal9000a]

i was thinking about building one for my 55 gal
3" X 20" with 2 coil .170 ID , 1/4" OD tubing 50' long
input/output tubing 1/4 ID
i don't have a sump so it will need a pump to push the water
is this pump too fast : Maxi-Jet MP 400 (106 gph)
i dont want to blow my tubing, am i crazy to do it that way ?

             |  |             <-- input from pump
             |  |
             |++++||          <-- valve
             |  |
             |  |
       ______|  |______
      | ______________ |      <-- "T" with adapor to coil tubing
      | |     _______| |_____
      | |    |  _____| |_____ <-- output to tank
      | |   _|  |_   | |
      | |   |    |   | |
   ___| |___|    |___| |___
   |                      |
   |                      |
   |.. ... ... ... ... ...|
   |    coil denitrator   |
   |.. ... ... ... ... ...|
   |                      |
   |______________________|

[timrandlerv10]

...ok, stupid question:

what kind of pump attaches to two .170 tubes on the input, and is variable from one drop a second (DURING CYCLE) and then full power (and how much should this be? after cycle...)?

i'm at 20ppm, and i would like to be closer to 5...

thanks.

tim

[hal9000a]

google "Mini-Jet aquarium pump MN404"
the slowest that i found