DIY Coil Denitrator Plans

[rsman]

1.) If you have 2 coils how do you adjust them both becuase you would have one output you couldnt really adjust one from the other. 2 ways , put the adjusting valve before the coils or put the adjusting valve on the output, with option 1 you can adjust each individually which is only a little better on a small coil, option two which works ok means one of the coils might not cycle at the same pace which could extend cycle time .... maybee.

2.) If you have 2 coils do they BOTH get set at like 1 drop per sec so the putput is 2 drops per sec? with 2 adjusting valves you would adjust just like with one coil, with 2 valves its a good idea to be able to either pinch off or on a large systm close an additional on/off valve that would allow you to set the timing for 1 coil at a time. with 1 adjusting valve you just add the flow rates and assume the 2 are equal, or pinch off one input to set 1 coil, then set the 2nd by adding to the flow rate of the 1st,

now when reality comes in... you wont be running your coil anywhere near 100%, and you will only need to adjust the flow rate while its cycling so as long as its consistant it all good.

[niko5]

Sounds good... I was also thinking of this...

I am going to use some needle valves for my adjustlment.. if I put 2 valves on each coil 1 valve just a cheep JG fitting valve and the other being the needle valve I could shut off one coil at the JG valve adjust the first then cut it off with the JG valve and adjust the second then when i open the valve on each they needle valves will be set. Does that make any since?

[rsman]

thats what i was refering to when i mentoned the 2 valves in #2.

in a smaller system its value is decreased, in a large system its very important especially durring times of maintenence

[cristhiam]

Are you guys still using the denitrators? this is an old thread but I'd like to see how these are working.
What would be good for a 125 with no sump about 80-90G of water. how long of a coil do I need and how tall the denitrator needs to be. I have 14 fish:
3 yellows tail damsels
cowfish,
saifing tang,
yellow watchman goby,
jawfish,
tail spot blennie,
purple pseudocromis,
starry blennie,
2 clowns,
1 black clown,
and sand perch goby

Thank you

[jamesbuf]

If anyone is still following this tread, I've got a question. Could you in theory increase the length of tubing and increase the flow and still get full denitrifying properties?

[rsman]

still using 2 of mine, tore down the breeding setup over a year ago, not using that one.

if you extend the length you have to increase the flow, extend the flow to high, or have a flow failure and your unit wont function (and could crash in a bad way)

need higher processing rate, increase the number of coils, or increase both the diameter and the length

[jamesbuf]

I already have a 24" tall, 4" diameter denitrator that I made a few years ago for my 75 gallon at the time. Now that I have a 180, I was looking to use this one instead of making a new one. It has 80 feet of tubing already inside, so I was hoping that I could just hook up another 80 feet of tubing on the outside (connected to the inflowto the denitrator) and increase the flow. By having 160 feet of tubing, I'm hoping to increase the flow and still have the water de-oxygenated by the time it hits the bioballs in the center of the pipe. My only concern is that the anaerobic bacteria will not have enough time to break down the nitrates. Having a 4" diameter, I was able to fit quite a few bioballs in there. I'm going to buy the tubing and try my experiment, and just make sure to keep track of the water quality that comes out.

[cristhiam]

Ok I finished mine two 75' coils in one unit, two inputs one out, unit 26" hight 4" wide. I just hooked it up today, running it full flow, how long before I slowed down? or should I slow it down now? and then to a 1 drip per sec.? thanks for all the help.

[rsman]

james: like all bio filters the media in the chamber will have to react to the increased input, dont double the length, go to some length that you can control pick something like 10% longer or 20% longer ... something

crishiam: you can slow it down any time you would like, it like most things has several ways of making it work, run fast, run slow its all good running fast for a while might make the cycle faster, if everything in the world is working for you that weekend

[miatawnt2b]

ok, so what happens to a coil denitrator if you loose flow for a period of time?

-J

[cristhiam]

Good question if you go back to page 1, this is what I found

as for power failures your tank will be in trouble before the denitrator, though its effectiveness will drop quickly it doesnt become "dangerous" for 4 or 5 days or more depending on volume of the bioball chamber. reverse flow wud be bad, but also not dangerous, it shouldnt be setup to return under water, it should always flow or drip from an elevated point into the water, this does a few things but first off it removes the temptation to not check up on it every now and then, it also adds o2 to the water fairly quickly the water will be trying to give off co2 and "suck" o2 in.

bypass well that depends on plumbing, check valves no they are not required and only add problems, pre filter things (whatever really) are a good thing though

[32flavors]

ok, I know this is an old thread... I am moving into a 120 and it will eventually be stocked on the heavy side, so... let me get this strait:

I want 2-3 coils of 75' ea in a 4 or 6" x 24"?

Would 2-3 coil denitrators be better than 2-3 coils in 1?

With flow control on each input line or just on the 1 effluent?

Also, I really like the idea of using a coarse grade aragonite to help with pH issues, should I use it alone or with bioballs?

Thanks all!!

[rsman]

Good question if you go back to page 1, this is what I found

as for power failures your tank will be in trouble before the denitrator

freeky, I read that thinking ...do i remember this... go back to the page and Id hope I did know that. OOH well its all good.

ok, I know this is an old thread... I am moving into a 120 and it will eventually be stocked on the heavy side, so... let me get this strait:

sounds like a plan to me

I want 2-3 coils of 75' ea in a 4 or 6" x 24"?

.... I remember this also

use the smallest setup you can fit the tubes into.... those sizes are to big.

Would 2-3 coil denitrators be better than 2-3 coils in 1?

no 1 is better

With flow control on each input line or just on the 1 effluent?

whichever it only effects how you cycle the unit. put a on/off (ball valve or other) on both input lines and output lines it makes maintaining the unit easier as time goes on.

Also, I really like the idea of using a coarse grade aragonite to help with pH issues, should I use it alone or with bioballs?

re read the thread use your aragonite elseware and use bioballs here.

[wooden_reefer]

I have often wondered how the gaseous nitrogen, the product of denitrification, leave the denitrification coil?

It seems that any N2 gas has to leave from the outlet.

[rsman]

the coil isnt used for denitrification, but most leaves the exit port, saturated in the water, over a long period of time a bubble can form at the top of the chamber, a exit port high up on the chamber keeps everything in check. one of many reasons to put the output out of the water to drip into the water.

[s a v v o]

An inquiry from Oz.

I've just discovered this site, having also just read Don Carner's articles. I've read the whole thread. I have a 150-gallon system, with a small fish load and a heavy coral load.

I'm intending to build a unit that is about 40 inches high and a diameter of four inches. I intend to wind the coil around an inner tube about 3 inches dia. This will fit inside the larger chamber, and the end of the coil will discharge inside the inner chamber containing the media.

I'm a little confused about the internal diameter of the coil tube and its length . Don recommends one-quarter of an inch to three-eights of an inch ID.

If I use one-quarter inch ID, how long should the coil be?

How long should it be if it's three-eights inch ID?

I'm happy to make it as long as necessary to ensure the water entering the media is oxygen-free. I'll be able to continue to coil the tube, as it will fit inside the void between the inner and outer chambers.

Hope you can advise me.

Les, Marine Society of Queensland
Brisbane
Australia

[rsman]

Hope you can advise me. ok but you asked for it!!

when it comes to nitrate there is no such thing as a "heavy coral load" and a single denitrator with a 1/4"OD tube aprox 50' long in a 14" tall 2" diameter tube will do just fine on a 150gal system (this does assume tank + sump = 150g)

[s a v v o]

Thanks for your prompt reply.

Les

[kau_cinta_ku]

so will mine work fine? so far only been hooked up for almost 2 weeks and no change but i am guessing it will start in around a month. i have a 30" tall 4" od PVC pipe with 100 feet of 1/4" tubing running on the outside, filled completly with bioballs on the inside. my tank is 75 gal. with a 30 gal sump/fuge. here is a pic.

[s a v v o]

Sam, is your tubing 1/4 inch OD or ID? If it's OD, what is the ID? The tube I'm thinking of using is black garden sprinkler material (I think it may be polypropylene), with an OD of about 1/4 inch but only about 5/32 inch (4mm) ID.

One other question: I have a bag of coral rubble, ranging between pea size and pieces about one inch long and 1/4 inch thick. I can easily go out and buy plastic media, but I'm wondering if one may be more effective

Les

[rsman]

kau_cinta_ku:
so will mine work fine? it will work, it might take longer to cycle, but it will work just fine.

so far only been hooked up for almost 2 weeks and no change whats that mean ??? how fast is the flow, nitrates? nitrites? ammonia? pH?

i have a 30" tall 4" od PVC pipe with 100 feet of 1/4" tubing running on the outside, filled completly with bioballs on the inside. my tank is 75 gal. with a 30 gal sump/fuge. here is a pic. thats too long a tube and too large a bio chamber so expect a slow start. and the possibility of low but varrying nitrate levels

s a v v o:
The tube I'm thinking of using is black garden sprinkler materialthat stuff works just make sure you dont kink it, icemaker tubing resists kinks better just make sure you dont get any with holes in it some of these are designed to perspire or ?? with micro holes every however far apart.

One other question: I have a bag of coral rubble, ranging between pea size and pieces about one inch long and 1/4 inch thick. I can easily go out and buy plastic media, but I'm wondering if one may be more effective if you dont wanna buy stuff put the coil in the bio chamber and fill the rest with 1" lengths of 1/2" pvc you dont wanna use coral rubble you dont want the most effecient, it doesnt take that, you only want to slow the water flow across some media down. not stop it

[s a v v o]

rsman, thanks for that.

I've been through the thread again, 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?

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.

1. The coil tube receives water rich in O2 from the pump.
2. As bacteria colonise the tube, you have aerobics oxidising the organics and producing ammonia, nitrate and nitrate.
3. As long as oxygen lasts, oxidation will occur. The slow progress of the water ensures maximum contact time.
4. The aerobics will colonise as far along the tube as oxygen lasts.
5. When oxygen runs out, anaerobes start colonising the inside of the tube.
6. So part of the tube will be aerobic and part anaerobic.
7. When the water reaches the anaerobics in the tube, denitrification commences.
8. When the water leaves the bottom of the coil, it passes through the media in the chamber with a reduced amount of nitrate.
9. Whatever nitrate is left is then processed by the anaerobes living on the media.

So if a coil is 50 feet long and (just to pick a figure) the first 30 feet of it are aerobic, the last 20 feet are anaerobic. I'm not able to understand why another 50 feet of coil is a problem, as it too would be populated by anaerobes. Aerobic oxidation would be completed in the first 30 feet of the coil, and anaerobic denitrification will occur in the remaining 70 feet of the tube. I would have thought this would be a good thing.

If the chamber contains (say) one quart of media, the anaerobes here will process whatever nitrate is available. If you double or triple the amount of media, you are still treating the same amount of nitrate. The same number of bacteria will be present in the two or three quarts as there would be if you had only one quart (only enough bacteria will form according to the amount of nutrient).

I can understand that having a coil longer than necessary and more media than needed may be a waste of materials, but I can't imagine why it's not a good thing. I would have thought that the extra coil and media would provide extra capacity for more bacteria in case the system ever needs to process more than expected.

This is all based on an identical flow through the chamber irrespective of size.

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.

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.

As I said, if there's something I need to read, I'd like to do that. If you feel up to explaining this to me, I'd very much appreciate it.
Many thanks.

Les

[kau_cinta_ku]

the tubing i used is 250 O.D. x .170 I.D here is the link http://www.homedepot.com/webapp/wcs/...ctId=100057801

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.

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?

why would i get the possibility of low but varrying nitrate levels and not completly all 0?

thanks for the help so far. i have just been battling nitrates for so long i don't know what else to do. lol

[s a v v o]

Thanks, Sam.

Les

[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?