Sulfur DeNitrators

[logman17]

I've been reading a few threads on the use of Sulfur DeNitrators here on RC, namely this one:
http://www.reefcentral.com/forums/sh...light=korallin

and at other places around the 'net:
http://www.aquaculturemag.com/siteen...fs/PARAGO1.PDF
http://www.aquariumfish.com/aquarium...d=3793&search=

and I decided to order this one:
http://www.midwestaquatic.com/sulfur_denitrifier.htm

My questions are:

1) Does anyone locally use one of these, and, if so, how has it worked for you?

I've read where you can do away with CO2 bottles to feed into a calcium reactor as the effluent from a sulfur denitrator is at a low Ph, which can be fed directly into a calcium reactor without using CO2, so:

2) Has anyone tried this and does it work?

I'm trying to have a two-part solution to (1) getting my CO2 bottles filled every 2 months (only can fit a 5lb bottle under my stand) and (2) to allow me to take more time between water changes without elevating my Nitrate levels as well as always ensuring a low NO3 level.

Thanks in advance for anyone/everyone's input.

[Fishboy42]

I have read a bit on these and coil denitrators lately, as I think something like this would be particularly useful for my clownfish growout system. I think the benefit of this over the use of heterotrophic bacteria style denitrators is that you shouldnt need to feed/adjust quite as much.

There was an article in oct/nov 2004 of Coral magazine suggesting that simply adding small amounts of sulfur to aquariums with very high nitrate readings (hundreds of ppm) could bring the nitrates within reasonable ranges. This would support the idea of this "technology" anyway...

I tend to agree with Randy's opinion on their limited usefulness in helping out your calcium/alk levels though just based on the chemistry, although I don't have first-hand experience:

http://www.reefcentral.com/forums/sh...fur+denitrator

I would be interested to hear others' input too and to know how it works for you!

-Matt

[logman17]

Matt-
I read that article, too. I wouldn't be using it as a sole source of calcium and alkalinity - I've got an (oversized) Ca reactor for that. I am mainly going with it because it seems like a easy way to keep nitrate levels at 0 and limit my maintanence with the tank. I travel a lot for work and just for fun, so bi-monthly water changes are really hard to accomplish for me.

My NO3 levels are at 10-20 ppm here recently and I haven't done a w/c in 9 weeks. I am thinking I can get away with only doing water changes every 2-3 months if I use this filter, as the only reason I do water changes in the first place in my nitrate levels. My calcuim reactor puts all the trace elements and calcium into the tank that it consumes.

One of the reasons I have been hesitant about getting one was due to the initial cycle startup and getting high nitrite levels during that period. Midwest Aquatics innoculates theirs with bacteria prior to shipment and Rick from the site assured me that there would be no Nitrite rise with this unit. Plus it starts reducing nitrate almost instantly.
I was also worried about having to replace the sulfur media too often. Rick said the sulfur media would only need to be replaced avery 2-3 years, typically. The aragonite will need to be added to as necessary, which he said is usually every 6-10 weeks.

I would be interested to hear others' input too and to know how it works for you!

Matt - I'll keep this thread updated on my experience with this particular Sulfer DeNitrifier as my unit is due to arrive on Friday.

[Fishboy42]

The pre-innoculation and (very) infrequent media replacement really seem to be good points for this unit (I'm thinking/hoping "plug-and-play"). I see what you mean about the Ca and Alk--makes sense. I recently (5 months ago) added ozone to my growout through the skimmer and have been happy with the results (don't need as much carbon, skimmer more efficient, etc). The next step would be nitrate reduction without sooo many water changes (same situation as you I believe). I would seriously consider one of these units if it could help me in that reguard.

I look forward to hearing about your experiences. Thanks, you are probably helping me more than I'm helping you!

[Pickupman66]

I know the sulfur Coils are a bit more advanced, and may have a few different properties, but I built my own coil denitrator for about $25, and once it was up and running it was DRASTICALLY reducing my nitrates. my nitrates are almost nil at this point and that is only because I had a bad adjustment valve on it and didnt pay enough attention or teach my wife to check it. I have however replaced said valve and the coil is working perfectly at this point.

as far as the origional cycle of the unit, it does have a break in period where it can produce some Nitrite, however, in an established tank, you should have the bacteria necessary to compensate for it. Shoot me a message and I can tall you more about it. as for water changes, I rarely every do them. maybe every 3 months, but now that this is fully operational, it will maintain nitrate levels of almost undetctable.

[Pickupman66]

Here is a post I made at another forum about my setup.


One issue many reefers battle in their tanks is a high level of Nitrates. Ammonia and Nitrites are processed by Aerobic (oxygen consuming) bacteria, but the bacteria that process the NItrates into Nitrogen gas only thrive in an Anerobic (oxygen deprived) envronment. While live rock, sump sponges and sand beds provide a place for some of these bacteria, in many cases it is just not enough to handle the bioload of the tank inhabitants.

there are several ways to reduce the nitrate levels in your tank.

One way to reduce Nitrates may include using microporus products such as Seachem's Denitrator. While these products may work, they are expensive and not necessarily long lived. From reading Seachem's website, the Denitrator product they sell is a highly porus granule that can be used for substrate or placed somewhere in the sump.

For those with lots of light in the tank, such as Metal Halide or even VHO lighting, clams are a great choice for reducing their nitrates. Clams feed of this chemical, but they are expensive and if you dont have sufficient light, they wont last long at all.

THe most widely used method of using nitrates is regualr water changes. The theory is that by changing a large volume of your tanks water, you are basically diluting the nitrates. while this is true, they are expensive, time consuming and at times Messy.

A solution to Nitrate issues that is starting to catch on are De-nitrator coils. there are several commercial units on the market ranging in price form $70 to $300+. While expensive, these products are effective. But wouldnt you rather spend that hard earned $$$ on fish or corals? De-Nitrator coils are basically a very long piece of tubing coiled up inside a tube or canister with a slow low pressure flow rate. the tubing provides a surface for which the bacteria can attach themselves. in the first third or so of the tubing, you have the Ammonia processing bacteria. these bacteria use some of the oxygen in the water to turn the Ammonia into Nitrite. the second third of the tubing houses the Nitrite processing bacteria. THis bacteria uses the remaining oxygen in the tubed water to process the Nitrite into Nitrate. By this time, the water has been depleted of its oxygen content and the NItrate processing bacteria are allowed to thrive and thus process the NItrate into soluble nitrogen gas which is then expelled at the water surface of the tank or sump.

Knowing these principals, you can build a coil for under $30 not including a pump. mine cost me $22! I bought a 60ft length of 1/4 inside diameter black pvc tubing at Tractor supply Company. it cost me $.22 a foot. I then took a 24" piece of 4" PVC pipe and purchased 2 4"endcaps. I drilled 2 holes just large enought for the tubing to fit thru in one of these caps. I rolled up the tubing neatly and stuffed it into the pipe and ran the two tag ends of the tubing out of the cap with the holes. I then purchased a inline air valve (like used with aquarium air pump) and placed in on one end of the tubing so that I could control the water flow. the other end I hooked up to an existing pump with a low pressure outlet, but several here have used a 4gph fountain pump. I have mine adjusted to about 3-4 drops per second. That is all there is to it.

it will take about 6 weeks or so for the unit to become fully functional (cycle), but from what we have discovered, these devices work wonders on reducing nitrates.

Parts List:
50-60ft 1/4" pvc (air hose) tubing
24" section of 4" pvc drain pipe and 2 end caps (have heard of some using a large coffee can)
1 adjustable air valve
4gph fountain pump

Here is where I got some of my info.
2893.12 in reply to 2893.11

really it is not the volume going thru the coil or the volume it holds that is what is at stake. whether it is 50 ft or 150 ft long, you still should have the same ammount of water flowing thru it at about 1 gal per hour, but the longer tube will have more water in it at once. the principal here is to create an area of water that is deprived of oxygen, hence the length of tube. the first lets say 30 ft of mine contain oxygen using bacteria that convert ammonia to Nitrite and then oxygen using bacteria that convert the nitrite to Nitrate. It is the bacteria that convert the Nitrate to Nitrogen gas which then exchanges at water surface in tank. ( been reading alot myself) From what I knwo about this now, I would venture to guess that having a tube longer than what is needed for the bacteria to grow is unnecessary. Remember, the bacteria will only populate to what the tank needs to support the above processes.

here is what I have read...

http://archimedes.galilei.com/raiar/denitrif.html

http://www.aloha.net/~hqf/indexdondenitrator.htm

[Pickupman66]

By the way, it looks like a nifty little bomb...

[Fishboy42]

Thanks for that information Pickupman. Doing a DIY here was a thought at first, but I worried about constant adjustments and effectiveness. I'll post this question in the forum so that others who may be interested can read your thoughts as well:

I have a question about your denitrator. I've seen plans similar to yours, but I'm confused about the path the water takes. Does the water fill the PVC pipe itself after leaving the tubing, or does it simply go through the tubing without touching the PVC? After reading some of the links you posted I had a different "picture" of the water going into the tubing and through the coil (where the oxygen is used up) and then exiting at the bottom of the PVC pipe and flowing up through bioballs or other media (which, because the unit is sealed, would (hopefully!) be an anaerobic environment), where the actual denitrification would take place, and finally exiting through the top. I guess either method would work, but for a heavily-loaded system such as fish growout, I would be looking for quite a bit of denitrification capacity (surface area where the anaerobic activity would be occuring). What are your thoughts on this?

Thanks!

-Matt

[Pickupman66]

Matt,

if you invest in a good valve, you should not have any issues. same type of thing with the other "store bought" items. potentially, the valve may get clogged with debris picked up by the pump. as for my unit, the PVC is just to make it look neat and keep in a small package. theoritically you can just leave the tubing balled up under your stand. as for the other option of sealing the tube and filling it with bioballs, you can do that. it basically creates a large area of anaerobic water. in that setup you have to make sure it is fully sealed and you have to work pressure fittings in it and worry about possible leaks. by not going that route like I did, you have a fully enclosed loop with a very very slim chance for leaks.

we are dealing with an ecosystem. as with the cycle process of our tanks in initial setup and running thereafter, your tank will only have bacteria presednt to handle the bioload. if you ahve a bioload for lets say 4 fish in your system, and you double that load to 8, your ammonia will spike, and once the bacteria multiplies to compensate, then your nitrites will spike, and same goes for Nitrates. the deal with the nitrates is that in a tank with high circulation and high oxygen content may not have enough anaeorbic conditions to support the nitrate processing bacteria. hence with a coil you are creating a place for those. Take a tank wiht a bioload of 8 fish. reduce the bioload and the bacteria will die off as less chemicals are produced in the tank, and you may see a change in your ammonia nitrite and nitrate levels.

as for an extreme bioload tank such as a fish growout tank, adding the bioballs can be good as it is basically just a larger anaerobic environment IE more surface area. you could also accomplish it with a longer coil, or even adding a second coil. the best way to determine it could be to figure out how effective a basic coil is in our system. lets say it reduces nitrates by 6ppm/hour, and your tank produces at a rate of 3 ppm/hour. your tank has lets say 30ppm Nitrate. then every hour, you are reducing the nitrate by 3ppm and it should be clear in about 10 hours. now these number are generalized for the fact that I cannot do math very well, but you can see the point.

[Fishboy42]

Thanks for clearing that up. I understand the possible issues with leakage and the pressurized container that the bioball idea would require--I like that idea, but yours seems much safer.

About the ecosystem: my "tank" in this case basically has 2,000 growing fish in it at any given time. While a large trickle and fluidized bed handle the aerobic processes of breaking down ammonia and nitrites, there just isn't enough anaerobic area for denitrification, so nitrates build up, and that is what I had hoped to control with some form of denitrator. Although I'm constantly moving fish in/out of this system, I think the overall bioload is *fairly* stable (HIGH!).

[Pickupman66]

I hear ya man. my best idea woudl be to build one and get it up and running and go from there. for the cost of the materials, you could build a couple. keep in mind that the is not much volume flowing thru this. my output is somewhere like 4-6 drops per second. just under a trickle. too fast and the water does not get depleted of oxygen, too slow and the nitrogen gas can make the water smell like rotten eggs. If keep in mind, it does all 3 forms of chemical conversion. I have heard of folks seeding it with like 4 grains of sugar and just letting the water sit, but I chose to just go ahead and hook it up and let it go naturally...

[logman17]

Thanks for the input, pickupman
I'm glad to know that denitrators work for you, I hope the sulfur version works similar for me.

After talking with Rick from Midwest Aquatics, I realized that using the effluent from the sulfur denitrator to feed the Ca reactor is not the best way to go as the Ph drop in the sulfur denitrator is proportional to the amount of nitrate being reduced, so it wouldn't be as consistant as using a CO2 drip.

I'll keep this thread updated if anyone is interested in the results.

FWIW, I did measure my parameters last night. They are as follows:

Ph - 8.1-8.3(swing from night to day) measured with a milwaukee meter
Calcuim- 445.1-464.5 (measured with a Pinpoint calcuim meter)
Salinity - 1.0245 (measured with a pinpoint meter)
Alkalinity - 180 ppm (measured on a Hagen test kit)
Nitrites - 0 (measured on a Hagen test kit)
Nitrates - 30 (measured on a strip and also a seachem test kit)

Hopefully I will be able to set up the sulfur denitrator this Saturday and I will take measurements every so often and keep this updated.

Thanks for the input and keep it coming

[fishdoc11]

FWIW elevated nitrate levels are typically caused by detritus building up somewhere in the system, under rocks, in shallow sandbed, on filter floss/bio balls etc.......If you remove that you will get rid of your nitate problem

[logman17]

FWIW elevated nitrate levels are typically caused by detritus building up somewhere in the system, under rocks, in shallow sandbed, on filter floss/bio balls etc.......If you remove that you will get rid of your nitate problem

I'm sure that is exactly what it is. When I do water changes, I use an Eheim 2217 with a gravel cleaner attachment to siphon all the detritus from the sump and vacumn the crushed coral substrate with it. I fill the eheim with filter floss and discard it after the water change.

Typically after a w/c my nitrates are undetectable. The problem for me is that we travel most weekends and my weekdays are hit or miss as to when I am home. My intentions are to do a w/c every other week of about 15%, sometimes that baloons into 5-7 weeks or longer without one. After I started adding up the cost of the corals in my display coupled with my desire to have everything in my tank thrive, I realized that I needed another option.

I figured that the sulfur filter will keep my nitrates down to acceptable levels in between water changes. I may be jumping the gun, but the cost of the denitrifier was a small price to pay for my peace of mind. Just losing a few of my favorite pieces would pay for the unit, so it was an acceptable solution.

I am also probably overstocked as I have 3 large fish and 2 smaller ones. They are also messy eaters, so that adds to the problem.

Keep in mind that my nitrates are currently at around 30ppm. 9 weeks ago they were at about 3-5ppm. So really they increase at a rate of about 2-3ppm per week. The sulfur denitrator should be able to overcome this amount and much much more (from what I've been told) for pennies a day media cost and bi-yearly maintanence.

Time will tell.

[fishdoc11]

Good luck
Let us know how it works.

[logman17]

Thanks Chris.

It will probably turn out like everything else in this hobby -

If it's too easy/good to be true, it usually is.

[Pickupman66]

Logman, good luck with it. I have had good success with my unit. testing tank wate rand then testing hte output of the coil you cna see a huge difference in the nitrates.

[skydancer]

Hey Logan, since you bought the sulfur denitrator from Midwest Aquatic I had a couple of questions if you don't mind.

1) What do they mean by 90% pre-assembled?

2) What do they mean by fast "CYCLES FAST"? Is the unit running at their facility for so many weeks prior to shipment?

3) How long will the media last?

4) How can you tell when it needs to be re-filled?

5) Can you buy the replacement media from them?

5) How can it be re-filled?

I'm considering buying one too.

thanks Alex

[logman17]

Alex-

Mine came in on Friday, but I haven't actually put in into the system yet.

#1:
the only thing I had to assemble was the pump on top. all fittings, tubing, etc was cut and fitted

#2:
they innoculate the sulfur with bacteria before they ship it. the instructions say not to rinse the sulfur media as the bacteria would be washed away also.

#3:
according to Rick @ midwest aquatics, the sulfur will last about 2-3 years, but the calcium carbonate will dissolve over time, they say the average to add the calcium carbonate is about 6 weeks as it dissolves

#4:
Don't know on the sulfur, but the calcium carbonate needs to be topped off as it dissolves

#5:
Yes - they sell the media.

#6:
refills with removing 8 wing nuts and taking the top off.

Alex-

I can tell you that Rick at Midwest Aquatics is a customer-service oriented guy. I originally ordered the small unit and asked if I could have it by Friday. They weren't going to have it to me until Monday, which wasn't a big deal, but he shipped me the large unit to arrive friday without any upcharge.
Also, I had a couple of questions on Saturday morning after I started playing with it. I emailed Rick thinking I would get a reply on Monday, but he emailed me right back and even followed up on Sunday with an email.

If you are thinking of getting one, consider Midwest Aquatics. They have been nothing short of impressive and would definately recommend them highly.

Also-
I should be able to finish the install of mine by the weekend and I'll keep updating.

[picture the reef]

Maybe a dumb question but what is involved with the "install".

[skydancer]

Thanks for all the info Logan. Keep us posted on the results. Do you know the starting value of your Nitrates?

[logman17]

Well-

The unit is currently up and running. I had a problem keeping the siphon from the main tank to the unit. Problem fixed.

It is currently running in a closed fashion for the 2 hours per the instructions, then I will run it a 1 drip per second for the next 3 days.
After that, I can go between 3-6 drips per second.

As of right now, my readings are as follows:

Ph - 8.1-8.3(swing from night to day) measured with a milwaukee meter
Calcuim- 445.1-464.5 (measured with a Pinpoint calcuim meter)
Salinity - 1.024-1.025 (measured with a pinpoint meter)
Alkalinity - 180 ppm (measured on a Hagen test kit)
Nitrites - 0 (measured on a Hagen test kit)
Nitrates - 30-35 or so (measured on a strip and also a seachem test kit)

I will take more reading this weekend after I get it in the full drip mode.

[jnb]

I have one coming very soon - will try to post before and after and the experience of getting it going.

[jnb]

could you pls describe the siphon issue and solution so I can get past that if needbee - thanks to you

I am trying to envision fileter the intake sionce the tube is smallish and particles (like my wandering bubble algae) does not clog the intake

Originally posted by logman17
Well-

The unit is currently up and running. I had a problem keeping the siphon from the main tank to the unit. Problem fixed.

It is currently running in a closed fashion for the 2 hours per the instructions, then I will run it a 1 drip per second for the next 3 days.
After that, I can go between 3-6 drips per second.

As of right now, my readings are as follows:

Ph - 8.1-8.3(swing from night to day) measured with a milwaukee meter
Calcuim- 445.1-464.5 (measured with a Pinpoint calcuim meter)
Salinity - 1.024-1.025 (measured with a pinpoint meter)
Alkalinity - 180 ppm (measured on a Hagen test kit)
Nitrites - 0 (measured on a Hagen test kit)
Nitrates - 30-35 or so (measured on a strip and also a seachem test kit)

I will take more reading this weekend after I get it in the full drip mode.

[logman17]

Real stupid problem:

I had a bad suction cup on the airline hose holder. Every few hours or so the tube would pop out of the overflow and fall to the floor.

I used a rubber band on my durso standpipe and attached it that way.


Currently it is dripping out at 1 drip/second until this time Friday, then I will measure the output for No2/No3 to see what's happening.