DIY denitrators

Discussion about cichlid tank filtration

Moderator: Ken Boorman

Post Reply
fishrman
Posts: 8
Joined: Sat Aug 16, 2008 1:51 pm
Location: NE Philadelphia suburbs

DIY denitrators

Post by fishrman » Mon Aug 18, 2008 12:53 am

Hey Gang:

Jason here, a new person to the group. I have been keeping these little beasties for about 3 years now and I am thoroughly addicted to the hobby. Lately I have been researching commercial and DIY denitrators because of reports of fewer water changes and also because I like the idea of using something more natural to aid in the filtration of my aquarium. I am striving to reach the greatest biological diversity in my tank and this would include types of bacteria (both aerobic and anaerobic). Have any of you experience and words of wisdom regarding these devices? At present I am leaning towards the more economical DIY coil denitrators. I am interested in hearing both successes and failures along with details.

Thanks for your consideration,

Jason (fishrman)

Bas Pels
Posts: 2241
Joined: Fri Mar 03, 2006 9:17 am
Location: Nijmegen - the Netherlands

Re: DIY denitrators

Post by Bas Pels » Mon Aug 18, 2008 7:35 am

Due to the problem of incomplete denitrification, after all, nitrate is not neutralized in 1 step, but in a lot, I never dared trying it

Incomplete denitrification produces toxic products, and I would not want to risk this. Further, before denitrification takres place, the water must be deoxygenized - almost completely. This prohibits any significant waterflow, and thus makes a denitrificator unusably large to have any effect

Finally, nitrates are produced together with phosphates. These phosphates are not neutralized in a denitrificator, and will still have to remouved by waterchanges

So, why bother?

Alternatively, one could try to remouve nitrates and phosphates together. A solution would be by growing plants in a seprerate part of the filter. However, again, this part would have to be rather large to have any affect

fishrman
Posts: 8
Joined: Sat Aug 16, 2008 1:51 pm
Location: NE Philadelphia suburbs

Re: DIY denitrators

Post by fishrman » Mon Aug 18, 2008 4:47 pm

Thanks for your reply Bas Pels:

"Due to the problem of incomplete denitrification, after all, nitrate is not neutralized in 1 step, but in a lot, I never dared trying it.Incomplete denitrification produces toxic products, and I would not want to risk this."
---My understanding is that the device would take approximately 2 months to cycle completely, with ammonia and nitrite being produced until that point. These would be managed by partial water changes.

"Further, before denitrification takres place, the water must be deoxygenized - almost completely. This prohibits any significant waterflow, and thus makes a denitrificator unusably large to have any effect"
---The plans that I have looked at achieve deoxygenated water by means of a 24-40 foot length tube with a 1/4-3/8 inch diameter. This is housed within a pvc pipe with diameter 3-4 inches and length 1-3 feet. To regulate the flow, a valve is attached to the output and set to 1-3 drops per second (something like that anyway). With the flow reduced by the valve, the water slowly creeps through the tube coil which is inhabited by aerobic bacteria. The idea is that the aerobics will consume the oxygen by about 2/3 of the way through the coil, leaving the rest of the coil and remaining space in the pvc clyinder O2-free. With the coil flush with the inner wall of the cylinder, there is a space left to be filled with plastic filter media. The media serves to further the stagnation process and also to provide greater surface area for the anaerobics to colonize. People have used many materials for this but "bio-balls" seem to be the #1 choice as they are reported to help prevent clogging. Returning to the beginning of the process, those that have used DIY denitrators also use a prefilter sponge to prevent debris from becoming trapped inside the coil and cylinder.

"Finally, nitrates are produced together with phosphates. These phosphates are not neutralized in a denitrificator, and will still have to remouved by waterchanges"
---True. This and some other by-products would be the only reason to perform water changes when using a denitrator. From what I've read, it takes a good long while to build up harmful levels of phosphates in the aquarium, especially in a freshwater tank (no corals to worry about). People that have had success with denitrators change their water about once every 3 MONTHS to remove phosphate and silica when the device is fully cycled---so I have read in various sources.

"So, why bother?"
---(see above again)

"Alternatively, one could try to remouve nitrates and phosphates together. A solution would be by growing plants in a seprerate part of the filter. However, again, this part would have to be rather large to have any affect"
And would only be effective as long as the plants are actually growing. Refugiums are like separate tanks for plants and will therefore require maintenance of there own. And a high output lighting system to provide the energy for photosynthesis ($$big bucks$$). And yes, it would have to be rather large. The plants would need to able to tolerate hard, alkaline water and also have a fast rate of growth in order to consume enough nitrate and phosphate to make it worthwhile. Have you found any of these? What is your success rate with this method?

The principles behind DIY and commercial denitrators sound reasonable to me but I would like to hear more feedback, particularly from any individuals that have experience with them.

Thanks,

fishrman

Bas Pels
Posts: 2241
Joined: Fri Mar 03, 2006 9:17 am
Location: Nijmegen - the Netherlands

Re: DIY denitrators

Post by Bas Pels » Tue Aug 19, 2008 1:40 am

fishrman wrote:Have you found any of these? What is your success rate with this method?
As you could have read above, I'm a waterchanger. However, I have rather good experiences with Pistia, and I know research is done into Lemna to produce food

both are floating plants, an other option would be Elodea in the water - but Elodea would require more care - continuasly replanting the tops et cetera

fishrman
Posts: 8
Joined: Sat Aug 16, 2008 1:51 pm
Location: NE Philadelphia suburbs

Re: DIY denitrators

Post by fishrman » Tue Aug 19, 2008 12:13 pm

Bas Pels wrote:
fishrman wrote:Have you found any of these? What is your success rate with this method?
As you could have read above, I'm a waterchanger. However, I have rather good experiences with Pistia, and I know research is done into Lemna to produce food

both are floating plants, an other option would be Elodea in the water - but Elodea would require more care - continuasly replanting the tops et cetera
Yeah, man. You made it very clear----I get that you're a water changer. So am I. More directly then, I'm looking for information specifically about DIY (or commercial) denitrators from people who have ACTUALLY used them---not opinions about one thing or another. I've heard plenty of opinions from individuals that don't want to risk it and have never TRIED to use one. That's not what I am asking for. I'm asking for information from people who have used one and failed or used one and succeeded. I've heard people's fears :shock: about denitrators--that can't help me at this point.

So, with that in mind, if there is anyone who has ever used one of these devices PLEASE speak up. Bas Pels, I appreciate your interest in trying to help. I just think you may have misunderstood what kind of information I was looking for. I hope this post clarifies my position. :D

Thanks and happy fishes,

fishrman

User avatar
James Shingler
Posts: 320
Joined: Sat May 20, 2006 4:45 pm
Location: UK Essex/Herts
Contact:

Re: DIY denitrators

Post by James Shingler » Tue Aug 19, 2008 6:34 pm

Best replies prob from Marine fishkeepers.
eg http://www.aquariumpros.ca/forums/showt ... hp?t=18394

Its so simple I hear but when even simpler water changes will do the trick for us freshwater guys not many prob try it.

fishrman
Posts: 8
Joined: Sat Aug 16, 2008 1:51 pm
Location: NE Philadelphia suburbs

Re: DIY denitrators

Post by fishrman » Wed Aug 20, 2008 6:22 pm

Good call on the marine forums. I'll see if they can shed some light.

Yeah, most of the reason I want to try it is that I'm a big nerd who would get a kick out of making the nitrate cycle in my tank a more or less closed circuit. If it were economical for me to concstruct some kind of automatic water changer to simulate the natural inflow/outflow of a real lake then that would also be very cool. I haven't looked into it because my hunch is that would be a little more complicated than denitrification.

I'll tell you guys what: If I do end up building one of these things and it is as easy and effective as I intitially thought (without any fish loss), then I'll post my results up in this forum too.

Thanks again,

fishrman

User avatar
Lisachromis
Administrator
Posts: 2854
Joined: Tue Nov 25, 2003 9:11 pm
Location: Ontario, Canada
Contact:

Re: DIY denitrators

Post by Lisachromis » Wed Aug 20, 2008 7:38 pm

If you do this on a FW setup, why not do it on a blog? We can watch the progress then.

bonytounge
Posts: 1
Joined: Tue Nov 17, 2009 11:19 pm
Location: Windham, North East Ohio
Contact:

Re: DIY denitrators

Post by bonytounge » Tue Nov 17, 2009 11:58 pm

well there is a better way the the coil your talking about doing. use of Sulfur Denitrator is a very good way to go unless you are trying to maintain a low pH due to the subtrate used it buffers for pH above 7.5 or possible to get around 7. also cycle is within days. keeps it around 5ppm once up and cycled but if built to large then you would have to feed the chamber.
125 gal tanganyika 20 gal tanganyika 29 gal black moscow guppy 40 gal crs shrimp
150 gal reef 65 gal reef 65 gal salt 29 gal salt
reptiels,parrot's, 20 plus years in the hobby and still know nothing

Ken Grimmett
Posts: 231
Joined: Wed Dec 30, 2009 11:10 am

Re: DIY denitrators

Post by Ken Grimmett » Sat Feb 20, 2010 9:07 am

What are the space requirements for a denitrator setup for lets say four 75gal tanks.
The future is what you plan for, life is what you get, enjoy it.

User avatar
fmueller
Posts: 454
Joined: Sun Sep 30, 2007 9:50 pm
Location: Auckland, New Zealand
Contact:

Re: DIY denitrators

Post by fmueller » Tue Mar 09, 2010 11:44 pm

fishrman wrote:If it were economical for me to concstruct some kind of automatic water changer to simulate the natural inflow/outflow of a real lake then that would also be very cool. I haven't looked into it because my hunch is that would be a little more complicated than denitrification.
You can built a DIY automatic water change system that very closely approximated the inflow/outflow of a real lake for about $20 to $30, and it is A LOT easier than any denitrifier I have ever read about. For details of the automatic water change system see my site.

Changing water is simple. As you have pointed out yourself, the only valid reason to replace it by something as difficult as selectively removing nitrate is if you are looking for a challenge. However, when selectively removing nitrate don't forget that biological systems are a lot more complex than a simple concept like the nitrogen cycle would lead you to believe. Nitrogen is an obvious waste products of your fish's metabolism. It is produced in sufficient quantity that simple test sets can be made to determine how much of it is in the water. That's why everybody is talking about nitrate - and maybe phosphate and a couple of other things.

However, these compounds are just examples for a gazillion waste products your fishes produce. Biological systems are infinitely complex, and some of those waste products might be produced in minute quantities and have never been researched. That doesn't mean they can't be harmful if you let them built up. By doing a simple water change, you get rid of all of those waste products, and you replenish essential trace elements at the same time. It's like hitting a big reset button to bring your system back to standard parameters.

Imagine somebody had bothered to find out about all the waste products a fish produces, then researched all the trace elements it needs, and asked a group of scientists to create a simple, one-step method to remove all of he waste at the same time as replenishing the essentials. The scientists would have thought about denitrators, dephosphators and dewhathaveyous, and in the end they would have thrown up their hands in despair.

Instead it was probably the mom of the first kid who kept tadpoles in a jar who dumped out the old water, added new, and never realized what an ingenious thing she had done. Water changes are such a simple and elegant solution to a seemingly insurmountable problem that I marvel at the concept every time I do one!

Frank

D.W
Posts: 1
Joined: Fri Apr 30, 2010 6:27 am

Re: DIY denitrators

Post by D.W » Fri Apr 30, 2010 6:31 am

yea water changes are great, if your tap water isnt 50ppm Nitrate :shock:

User avatar
fmueller
Posts: 454
Joined: Sun Sep 30, 2007 9:50 pm
Location: Auckland, New Zealand
Contact:

Re: DIY denitrators

Post by fmueller » Fri Apr 30, 2010 9:14 pm

Are you on well water or city water? At any rate, 50ppm nitrate in the tap water is not normal. Complain to the city, or if you are on a well, try to track down the problem. There could be sewerage seeping into your well water. I'd be worried about more than just the fish! Before you panic though, make sure that your nitrate test is accurate. You could test some bottled water for comparison.

blackghost
Posts: 139
Joined: Tue Dec 29, 2009 4:04 pm
Location: Cumbria, UK

Re: DIY denitrators

Post by blackghost » Fri Apr 30, 2010 9:37 pm

I dont know about the USA but here in the UK our water authorities work to a maximum of 50ppm nitrate in our water supply. I'm lucky with 5ppm, but a lot of areas arent. Even so, I filter all my tapwater through Underworld Polyfilter before it goes near a tank, so that ALL contaminants - known and unknown - are removed (more or less) at source (there is a list somewhere of the 40+ toxins that are acceptable and regularly found in tapwater. They all have maximum 'permitted' levels).It's a thrill doing a water change when you know the water is good. One polyfilter last me for about 6 months filtering 150 gallons per week. With 50ppm it wont last as long but it should still be worth doing.

I would hate the idea of leaving my water for months, even if I had zero nitrates. fmueller your first post is excellent. I agree all the way, and now I'm off to look at your auto-water changer.
:D :D :D
Mark Wright

Ken Grimmett
Posts: 231
Joined: Wed Dec 30, 2009 11:10 am

Re: DIY denitrators

Post by Ken Grimmett » Sun Feb 13, 2011 10:46 am

Hey Guys and Gals...

I just reread this topic and I have one though....

As I get older I pay more attention to what the media reports on that concern me. One of the current topics that are increasingly in the news is water conservation. My guess is that the way our governments will force conservation is through taxes on water usage. The cycle of this topic in the news is becoming more common than in the past. One day in the future, I don't know when, this will happen. I would like to have solved the high water usage we currently have before that future forces us to solve it.

Sounds like a good project for someone’s Master or PHD thesis.
The future is what you plan for, life is what you get, enjoy it.

Tobiascute
Posts: 1
Joined: Mon Feb 13, 2012 10:32 pm

Re: DIY denitrators

Post by Tobiascute » Mon Feb 13, 2012 10:48 pm

This is accomplished by buying a commercial or DIY denitrator. Our coil denitrator is feed oxygen rich water via a pump.

Post Reply

Return to “Filtration”