Tired of spending all of the time and money on performing endless water changes to keep your nitrates in check? Here are simple, inexpensive DIY Coil Denitrator plans from Don Carner.
More: What Is A Coil Denitrator and How Does It Work? Nitrate isn't good for our systems, be they FO (fish-only) or reef. You can buy a commercial denitrator that cost a ton of money, or you can ...
More: "Vodka Method" of Nitrate Reduction Really works!! Share a vodka martini with your fish and watch your nitrates drop like a rock.
Graphics by Don Carner
Comments
I built the coil denitrator about 4 months ago and followed the specs from don carner …..conclusion it just doesn’t work !!!!!
i built the coil denitrator about 7 months ago , i am still waiting to see any difference in the nitrate levels in the tank and the nitrate levels coming out of the denitrator please respond and explain this to me ………Bill
When I first search for and found this article over a year ago, I was overjoyed. Much to my dismay, I feel I have been somewhat lead astray. After reading the article, I attempted to email Don Carner at the email provided and received NO responses. The item in question are several; how big a pum( how many GPH), what type of fittings are used to connect the tubing on both sides of the PVC? ANyone, please fill in the blanks!
Has anybody made one of these and had it work?
Would be nice to know before I built my own…
Thanks!
I am going to build one of these but honestly the plans seem rather weak. Using Chemistry basics it seems that it won’t be able to handle the bio-load. It would be nice for the author to surface and for someone out that to tell us of some success.
i has build this 2 times…. and both of them has 0 nitrate output…. but we must be patient… because the Denitrator need to has a nitrogen cycle too… and need 1 month to archive 0 nitrate output….
Happy to say that after 1 week of operation the output of my denitrator is 0ppm!
I used 1m of 100mm pipe with an inspection flange top and bottom, 30m of pre coiled air hose filled with bio-balls.
All of the pipe fittings can be found here:
http://www.johnguest.com/range_spec.asp?a=PIPM&rs=1&id=23
I have also been feeding the denitrator with 12ml/day of 1:3 vodka/water mix.
I just built my first denitrator. After studying several different plans, I spoke to my LFS, a chemist, and a biologist. I made changes to this plan based on their professional advice and comments I’ve seen on forums.
I have a 2-foot length of 4-inch PVC with 100 feet of tubing coiled inside. I filled the center with crushed dolomite with a plastic screen on top. The return line has a tee connector. The water runs straight through, and a very small air pump bubbles into the “T” part. Final output goes to the intake venturi of a power head. Air and water valves control output rate so precisely that I can set it to drops per minute or steady stream.
I hooked this up about a week ago. I plan to test nitrates and seed it with BioZyme after tonight’s water change. Will keep you posted.
OOPS! Water coming out of this thing is showing nitrate level at SIXTY ppm. Thank goodness the tank level was much, much lower!! I slowed it down and used BioZyme to seed it. Will check it again this weekend. If this doesn’t fix itself, it’s death to this unit. Anyone has suggestions, I’ll take them.
OK. A week later, with a slower flow, Nitrates coming out of the cylinder are down to 40 ppm. I tested all I can except Calcium. The pH (8.2) is just a little bit lower than the tank (8.4) and the KH (10) is a bit lower than the tank (12). Ammonia, Nitrites, and the dreaded Phosphorus are all zero, as expected. Tank Nitrate level is up slightly, but not as much as I feared it could go.
Maybe I wasn’t patient enough? A different plan from another site says to seed it and stop the flow. I am a little uncomfortable with that. I’ll give it another week or so.
Based on the comments I think there is some confusion with how this thing works and how long it takes. First the flow rate isn’t precisely measured in GPH, it is a visual estimation. Using standard airline tubing, the rate should be so that it is not a solid stream but almost a solid stream of drips… so each drop coming out is right behind the other to almost appear as a solid stream. It should take a while to cycle just like the tank… higher nitrates than what is in the tank indicate that the anaerobic bacteria has not yet proliferated the final stage of the denitrator but should come in due time.
There’s definitely a lot of confusion on these. I emailed a few people and got one response. He said exactly this: “It has to go drip… drip… drip… Not dripdripdrip” What the heck does THAT mean? I realized the flow rate had to be very slow, but not slow enough that you get a buildup of sulfides. It has a leak and needs to be repaired, but I was finally successful with this thing. It lowered my nitrates but never got them to zero. When it broke, my tank level did go up.
I don’t pump water in. Instead, the water siphons through hard vinyl tubing and returns via help from a low flow air line so I can fine tune the flow. I got it to about 90 drops per second and that seemed to do the trick. Slower might be better, but I never messed with it after I got it working. I used 1/4″ ice-maker supply tube the first time, but I’m switching to 3/8″ this time because I had coralline growth plug the intake a few times.
A friend of mine told me he built one but it plugged up in about a year and a half, and then he threw it away. My LFS guy says the coil needs to be 1,000 feet or you’re not doing anything, so I’m not so sure I’m going to put it back together. Meanwhile, the tank nitrate level dropped dramatically as the tank has matured, so do I really need to rebuild this?
This thing works! I just built two. The nitrate coming out from the reactors are 0ppm. However, I modified it as I can’t find such a big cylinder to squeeze all the tubing in. I have 50m of airline tubing (1 whole roll) outside a 750cc bottle. In the bottle I coiled around 6m of the tubing followed by bio balls as described by this website.
One thing is the flow rate is not making my tank nitrate level 0ppm, because the output is slow (I’ve set the drip to the max, which is around the transition from a drip to a steady stream). That’s the reason I built 2, and now my tank nitrate level is around 10ppm. Before the denitrator, my tank nitrate level was around 80ppm. I’m using a fluval 304 (1000L/h) to power the two denitrators.
I have been using a denitrifier for NO3 for 10 years or more and never do water changes using Methanol as the agent instead of vodka. I have 0 nitrates in my tank. You must let the system you set up outside your tank cycle till it reaches 0 before ever dosing your tank, using air bubbles or a small pump to keep active movement at all times in the chamber. You should dose drops of agent for approx 30 minutes a day till cycle reaches 0, preferably using a dosing pump with a 2 cycle timer, turning off the 2nd cycle to dose the tank until the denitrater has reached 0 Nitrate PPM. Water changes should be done in tank at least every 3 months, at least 20% of tanks gal just to refresh some of the trace elements lost by protein skimmer and natural loses to prevent meltdown of tank eventually. Once unit has reached 0 NO3, than tank should be dosed for 20 minutes for tanks up to 75 gals and 30 minutes for larger tanks, and then 2nd cycle dosing Methenal to Denitrafier every day for 20 minutes, be sure to check NO3 before flushing back to maim tank, VERY IMPORTANT. It may take 24 hours before NO3 returns to 0. When cycle finally reaches 0 daily, than start to reduce the amount of Methenol you use to dose Denitrafier on a daily basis. I hope this helps. I dose my denitrafier now for 10 minutes using a dosing pump and flush to tank for 20 minutes every day. Now that its established
I have noticed that nobody here mentioned anything about the anaerobic bacteria needing to be kept from light. They proliferate in darkness. Yes, they need a catalyst, and you need to research different recommendations and decide what work best for you. As was mentioned, the rate of the return to the water column os not a GPH flow, but is rather a slow drip rate. Also as was mentioned, the water coming from the denitrator must have achieved 0 ppm before returning to the tank. The length of the tube makes a difference. What needs to happen is for the oxygen in the water entering the denitrator tube must become completely oxygen depleted before it reaches the anaerobic bacteria. They cannot work in an environment that has too much oxygen or too much light. One of the reasons for the catalyst is to kill the oxygen so the anearobic bacteria can proliferate. I hope that helps. As for amount and rate of feeding the catalyst, it depends on the length of the tube in the denitrator, and the flow rate (which should be fairly slow). The necessary anaerobic bacteria will not grow in the tank because there is too much light and too much oxygen. I hope that helps.
OK well YES the confusion is the flow rate I let mine run fort about 4 weeks with a pretty fast drip rate. The i turned it down to as close to exactly one drip per second. ( 60 drops per minute ) and a few days later the water coming out of the coil is now absolute zero. Mine coil is in a PVC pipe one foot long and about 60 foot tubing coil. I use spastic scrubbers for the media.
My question to anyone who can give me a FOR SURE solid answer is…. Dose the thing have to run so slow as to test completely zero or can it run a bit faster and just test LESS then the main tank? My worry is if I turn it up to the point that SOME nitrates are showing in a test That the oxygen might get to the anaerobic bacteria and kill it. Please only answer if you are sure Cuz I don’t want to ruin the entire thing and need to re cycle it. Thank you OR if your not sure Just please say your not 100% sure HA HA Thank you again These units have huge potential I am planning to add two more BIGGER ones to my system.
I wanted to point something out that I forgot to mention in the above post. I have never seeded or dosed this De-nitrate coil. Again With the drip rate at 1 drop per second After 4 weeks I am now getting ZERO nitrate out of the drip end of the unit. I have not NEVER dosed or seeded with or fed it in any way whatsoever. I simply built it and started it up using only the tank water flow threw it. ZERO ZERO ZERO and that is the absolute truth.
This leaves me to conclude that seeded feeding or dosing this thing is not necessary AT ALL. perhaps it might cycle faster But 4 weeks isn’t long to see results in my opinion
For those of you who refuse to believe it works Here is ROCK SOLID PROOF watch this clip
http://www.youtube.com/watch?v=X306Ef-5jgA