Coil Denitrator

[dgbnyc]

Hi there,
Been a while but perhaps I can get this thread started again.
Can you help me understand what is going on.
I'm trying to 'cycle' my coil and I have BOTH the sulpher smell and nitrates! Could this suggest my tube is too long or what?? I'm at something of a loss!
Thanks in advance

 

[richdragon32]

sulphor smell suggests that the flow is too low, or the tube is too long. How long is your tube and what is the drip rate?

Richard

 

[rsman]

also do you have nitrites in the tank ??? or just at the output?

 

[clay3482]

HELP please

HELP please

I hope you guys are still around. I found this thread and I am very interested in it. I have a 33 Long and a 55 both of which have live rock and about 1" - 2" of aragonite shells on the bottom. I have about 2 pounds of Rock per gallon on each tank.

Problem is my Nitrates stay elevated, I should do more water changes but I dont. Both tanks have skimmers, Fuge's, and canister filters.

Neither tank is stocked heavy.

I found this link on the denitrator coil.

http://2hot2cool.com/4/afishianado/afishian.htm


Does this look like a good way to go?

Do you think it might help me lower my nitrates?

Thanks for your help.

 

[rsman]

use a continous length of 50' would be better, more importantly dont use connectors INSIDE the unit to extend each coil, it doesnt need to be as tall, and skip the quick connect fittings

 

[Fishguru]

ok, i'll be the stupid one to ask what good the coiling actually does for this. why not just have it like an inline filter.....input one end, output other......

 

[_-Nebuli-_]

if im not mistaken the coil allows for a large amount of time for the water to contact with bacteria that uses up all the oxygen in the water, that way the bacteria that break down nitrates, which have to live in oxygen starved water, can colonize the bioballs inside the chamber. that way when the water slowly moves up though the bioballs you have a maximum surface area inside for slow contact time with the nitrate consuming bacteria.
which is why you need to have the run off water going to an area of high turbulance so the water can fully reoxygenate itself before returning to your display.
if you didnt have the coils it would be just like adding bioballs to anywhere in your tank....which brings up other issues of having high nitrates...yada yada...

thats the way i understood it anyway.

HTH
Tre'

 

[clay3482]

ok so If I have it correct

ok so If I have it correct

Use one long piece of coil. around 50 - 75 foot. 75 being the max and 50 being the minimum.

Don't splice the coil, it needs to be one section, I assume to keep down the possibility of leaks inside the unit as well as a place for it to become clogged.

Skip the quick connect fittings and try to find somthing like a compresson fitting.

If above is true then only one last question

DO you reccomend using a siphon or a pump for flow through the unit? I don't know if a siphon would work, too simple i guess, but i worry that i might not get enough flow with a siphon only.

 

[clay3482]

another question

another question

Do you recommend this for reef tanks? I have 4 tanks, 2 are mostly fish while 2 are mostly reef. I have high nitrates on all 4 tanks.

One of my Fish tanks has a huge amount of Red Slime, I have the phosban going and my phosphate is under control, I was going to use this to get the nitrates down.

All 4 tanks have a skimmer, and a fuge. the mostly fish tanks also have a canister filter.

 

[rsman]

the coil allows for a large amount of time for the water to contact with bacteria
ok first off why dont we replace time with high surface area to volume ratio, if you say time it sounds like the water should stop, IT SHOULD NOT!!!

50 being the minimum
no 50 being the recomended really the minimum is like 20, but lets not all jump on that, just cause itll work doesnt mean we want it! to get a good flow thru it you need just under 50' if you go a little over your fine, too far and it depends.

I assume to keep down the possibility of leaks inside the unit i wont go into too much on this but you cant have a leak from 2 areas of the same pressure, one has to be higher, even if you did somehow get that leak without having the clog, it wouldnt matter, its ONLY because those micro pieces clog.

DO you reccomend using a siphon or a pump for flow through the unit? I don't know if a siphon would work, too simple i guess, but i worry that i might not get enough flow with a siphon only.
YES

did that answer the question

either will work just fine.

as for which tanks these will work on, they work on just about any fish tank FW/SW/FO/Reef/Preditor .... the one and simple catch is that these do nothing for phosphates, AND algae need both phosphates and nitrogen waste, and as they need more nitrogen than phosphates, if you use a very large unit on a small reef your plants will not export phosphates as they will become nitrogen limited, so to get good results in a reef you should think about sizing small, and use algae to xport the rest.

there perfect for FO's where phosphates dont matter.

 

[clay3482]

one last question

one last question

I hate to bother you. Please let me ask one more question if you dont mind.

I have 2 NANO tanks that I don't plan on using this on.

I have one tank that is mostly Fish , with 100 pounds of live rock. I use this as my Temp tank. It is a 55gallon. I have on this tank a Skimmer, a HOB Penguin filter (with the bio wheels off) and a HOB Canister Filter. I can not get the nitrates down (80 - 100 now)or the red slime gone - no matter what i do. I was going to add the coil denitrator to this tank.

I have another tank that is a 33g Long. This is my Main tank. It has 3 or 4 small fish and alot of Corals. This tank has a lot of Live rock, and HOB Skimmer, and a HOB Fuge. I was going to add a Coil denitrator on this tank to get the nitrates down below 20 (15-30 now). I was going to discharge the coil into the Fuge.

Please tell me if you think that this will help me with Both the 55 and the 33 . If i need to try somthing else let me know.

 

[rsman]

I hate to bother you. Please let me ask one more question if you dont mind. its not a bother or i wouldnt answer

is that 55 "temp" tank a cold water tank? if so use 2 coils in the exact same setup itll drop those nicely.

the single coil will do fine on even the 55 if its not a cold water tank, itll do more than fine on the 30

keep in mind this is a bio-filter and it must cycle, and while thats going on you must maintain proper flow, once its running they can be just inspected frequently to make sure you can see water coming out.

 

[pwest]

1/4" ID Tubing??

1/4" ID Tubing??

OK, I think I'm going to jump on the bandwagon and build one of these. I've got a 150g reef and a 30g sump with a small fuge w/macro in it. Although my nitrates are down now, they have sometimes loitered at 10 ppm or slightly above.

I'm concerned about the potential for clogs in the .17" ID tubing so I'd like to go with some 1/4" ID drip irrigation tubing instead. If I've worked out the ratios correctly I should use roughly 86' of the 1/4" ID tubing instead of 50' of the .17" ID tubing, and I could expect about twice the drip rate from this.

Finally, I'm thinking about using a short 5" or 6" diameter PVC pipe instead of a taller 3" or 4" one, and I've got a bag of Siporax that I plan to put inside.

Does all this sound OK, or should I just use the classic icemaker approach and not worry about clogs? If I go with the dripline, should I have a single coil or go for a double. Same question if I stay with the 0.17" approach--should I go with 1, 2 or even 3 of the 50' coils?

Many thanks for any and all comments,
Phil

 

[Tommyc]

bump

 

[rsman]

ive been really busy lately, i just have very little time, so instead of bumping a thread that you have not been posting to consider either clicking on the Subscribe to this Thread link or posting a question so that I can answer it.

additionally if you are considering a coil denitrator for your tank give us info about the tank, bio load (Na rise over X time), volume. anything that you think might be required for someone to fit a bio-filter on your tank.

 

[cduran02]

I found that the best way to cycle a de-nitrator is to fill it with some aquarium water, close the input and output on it with valves and leave it sealed for about 4 weeks. This will work even better if you have some medium (such as bio-balls or carbon in it). This actually gives the de-nitrator time to grow anaerobic bacteria without being constantly interupted by fresh water. Just make sure when you install the DN back that the output is fed into a high flow area of the tank where it can get aerated properly.

 

[rsman]

that is far from the best way to cycle a coil denitrator, its just the one that requires the least amount of work. it also takes longer. the problem with it is the coils need to cycle differently than the bio-chamber this is how they work. it can also be dangerous, more so when the tank water is lower in nitrates, *some* people do very frequent water changes to offset a high bioload and would use the coil denitrator to reduce the waterchanges to monthly/bi-monthly those people would have a coil denitrator that would not function. also you need to carefully dispose of the first couple passes of output so that you dont release any hydrogen sulfate gas. now if you built this unit in 2 parts the coil and a bio chamber seperately, you could setup the coils to run wide open and cap off the bio chamber for a week at a time and get better and faster results but without new tank water it wont cycle well, it will consume all of the nitrate too fast then there wont be any to allow more bacteria to grow.

 

[pwest]

I'll chime back in here. I went ahead and built a CD (coil denitrator) using 80' of 1/4" ID polyethelyne tubing (after I built it I saw that rsman recommends 120' for 1/4" ID, but some of the other internet DIY articles recommended 50'--I hope 80' is OK) and a bag of Siporax all inside a 13" tall 6" dia tube. As I said earlier, I've got a 150 gal tank, a 30 gal. sump w/a fuge. In the tank, I've got a few large leathers, some other softies, a 6" powder blue tang, a 5" foxface, 2 small clowns, a small spotted mandarin a small royal gramma and about 150 lbs of live rock.

The tank has been up and running for about 2 years and about 6 months ago I started seeing nitrates of about 10 ppm. I substantially reduced the amount of food I was giving the fish and started doing more water changes (still only about 15% every two weeks--not what's needed to get nitrates down, I know): the nitrate level just seemed to hang around 10. Over this time, all of my coral stopped 'thriving', and my large multiheaded Torch almost completely died and my candy cane coral did. My anchor and 2 leathers continued to look fine as did my green button polyps, mushrooms and zoos. Some of my green star polyps died and the rest was doing poorly.

A couple of weeks before I built the CD, I borrowed a fluval from a friend and started running it with carbon and Kent nitrate sponge. By the time I was done with my CD, my nitrates had gone back down to zero!! I hooked the CD up anyway and am letting it 'cycle' with a slow drip using gravity feed from one of my overflow's and emptying into my sump near my skimmer (lots of air). After hooking up the CD, I removed the fluval, but tossed the bag of nitrate sponge in my sump near the exit tubes.

Any thoughts about what I should do to monitor what's going on with the thing given that I've got no detectable nitrates on the input? I suppose checking the effluent for Nitrites would be a good idea.

-Phil

 

[cduran02]

I dont use a coil de-nitrator, just took a 3" diameter PVC pipe 36" long. Caped both ends with valves and filled it with nitrate spong. Filled the tube with some of my tank water with about 40ppm of Nitrates, there should be enough there to keep the bacteria nice and healthy.

I work for an R&D lab that focuses on environemtal remediation, spoke with our anaerobic chemistry expert and she said it should work fine. The nitrate spong in this case just acts as a housing for the bacteria, could actually use carbon or even live sand as long as its anaerobic. The only drawback is that the medium needs to be changed every 6 to 8 months. But I can fix that by running 2, 3 even 4 de-nitrators in parallel and change one at a time.

Also if you feed the output of your de-nitrator right into the reaction chamber of your skimmer you dont need to worry about gasses harming the fish.

 

[Tommyc]

ive been really busy lately, i just have very little time, so instead of bumping a thread that you have not been posting to consider either clicking on the Subscribe to this Thread link or posting a question so that I can answer it.

lol. rsman, you busted me with one of my own pet peeves. touche. I subscribed to this thread years ago. Was bumping because phil hadn't gotten any replies in two weeks. I hesitate to respond to posts when I don't have personal experience (and I don't in this area). Was hoping someone who had actually ran them would chime in. I can relate to being busy...on the road in FL for two months.....But I will take your advice and ask a couple questions for you or anyone else with experience.

Early on when this thread started you said you were of the opinion that 50' was the minimum length and 75' was better. More recently you've said 50' is recommended. I'm assuming we're talking about the same .17ID tubing discussed earlier. Has experience taught you that the longer length isn't really required?
Or are you doing a tradeoff (i.e. shorter length for slower flow)?

How'd your plan to string four DCs together feeding into a fifth chamber work out? Did you get the buffering affect you anticipated out of the fifth chamber?

I've got more, but I'll stop there. Don't have a specific tank I'm going to put one on....but since they're cheap and easy to make, I might make a few while I'm away from home for grins.

Tom