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Denitrator systems
- Thread starter Erich
- Start date
Satan's Milkman said:
I'd like to hear about experience with these sulfur denitrators myself. Years ago I did use other types of denitrators, and they did work, but were a pain to feed, and to regulate. I can see that the Korallin product has resolved the feeding problem. I'm not quite so sure about the regulation problem.
On a traditional denitrator, too much flow and reduction was incomplete, resulting in nitrite, too little and you got sulfates and that "rotten egg" smell.
I run a dual chamber sulphur denitrator and should be able to answer any questions you guys have about them. I've been running them for a couple of years now both with and without sulphur. I've went through all the constant regulation and feeding problems/issues and have finally come up with something that is easy to use and just works.
IMHO the brand you purchase doesn't make much difference. You can also build your own or pickup a cheap calc reactor and use that.
When I wanted to add my 2nd nitrate reactor, I picked up the "big" Coralife 500 gallon calcium reactor and used it. $160 or so and it works great. The Coralife (as well as most calc reactors) can be used out of the box as a nitrate reactor. You just don't hook up the CO2 to the unit but instead use sulphur or feed it vodka or sugar (for BIO style).
I've experimented a lot with them (media and feeding) and found the following to be the highest production of nitrate reduction for my systems. I presently have the Coralife 500 reactor filled 2/3 the way up with Siporax and 1/3 with sulphur beads. I then feed a second reactor which is filled 2/3 full of Siporax and 1/3 full of Calcium reactor media. The 1st chamber has the sulphur (food) and the 2nd contains the calcium media to buffer the pH. While I used 2 chambers one could be used just as easily or the 2nd chamber could be something like a phosban reactor filled 100% with calcium reactor media.
The Siporax never needs replacing and the sulphur beads only need replacing/added to when the reactor starts to loose a little functionality (about 9 months to a year). The calcium media needs to be added to/replaced every couple of months. By using 2 chambers I never need to disturb the first chamber when adding more calcium media.
In my setup I use 2/3 full chamber of Siporax. I could have also used Matrix or just went with all Sulphur beads. As the sulphur beads start to get used up they get smaller and smaller and start to have a "clogging" effect. With only 1/3 part of sulphur this clogging effect is much less noticeable and the effluent coming out of the reactor is much more stable. The Siporax is also highly porous and can host a lot more anaerobic bacteria then the sulphur beads alone. This to me has proven to be a nice combination of media.
The Coralife calcium reactor has a pH probe port at the top of it. Instead of using a pH probe I use a ORP probe. I think having an ORP controller (or at least monitor) is critical in getting a nitrate reactor to run correctly. You want the ORP reading to be in the negative (below zero) and kept between -50 and -300. Above -50 (going towards positive) the reactor won't be processing nitrates and in fact will cause nitrates to get higher. Below -300 you will start to produce hydrogensulfide. I target -170 and have mine on a controller and AquaLifter pump. The controller will turn on/off the pump to keep the ORP right in then -150 to -200 ORP range for optimal nitrate processing.
TIP: Most ORP monitors/controllers will not read negative ORP values. Since an ORP value is nothing more then a volts reading (mV) there is a little trick you can do. Cut the probe and rewire it backwards (+ to minus, - to plus side) or pickup a couple of BNC connectors and make a "crossover" cable (what I did). With the crossover cable everything reads backwards. Plus values will show up as ZERO (or negative) but the negative ORP reading show up as positive. Now any controller can be used. You just have to remember to think "negative values". With this logic in hand, when the ORP is reading +200 (really negative 200) you want to increase the flow a bit and when the reading is +150 (really minus 150) you want to slow the flow a bit.
With a slow flow pump (and resistor to slow it down even more, IE airline valve) and an ORP controller with the crossover cable, the nitrate reactor becomes a hands off piece of equipment that doesn't need constant fiddling with. Without the use of ORP monitoring/controller you have to test the effluent for nitrates and constantly adjust flow by a couple of drops a minute to get it dialed in. This gets to be a chore after a while.
There are many styles and ways to run a nitrate reactor. The above is only a description of what I've found to work well after much experimenting and use. The best advice I can give is to read the online pdf instructions at the manufactures websites for the unit and make sure you fully understand it's operation before purchase. I only mention this because a poorly setup or run nitrate reactor can create hydrogensulfide which can crash a tank if not monitored correctly.
Note: If you run a nitrate reactor you will loose the "natural" balance of calcium and alkalinity in your system. The calcium media in the nitrate reactor will add slightly to your calcium while the nitrate reduction process itself will use up alkalinity. So be prepared to buffer your alk more and if you use a 2 part additive be prepared to deviate (not a problem in itself but something to be aware of).
Carlo
PS I had to use one of these units prior to my basement setup because of space. If you have the space I'd recommend a good refugium with macro algae and a DSB first before a nitrate reactor as it's more natural, helps with phosphates, doesn't alter your calc/alk balance and is more hands off. You can also run a fuge on alternate light cycles if needed to help stabilize your pH range.
IMHO the brand you purchase doesn't make much difference. You can also build your own or pickup a cheap calc reactor and use that.
When I wanted to add my 2nd nitrate reactor, I picked up the "big" Coralife 500 gallon calcium reactor and used it. $160 or so and it works great. The Coralife (as well as most calc reactors) can be used out of the box as a nitrate reactor. You just don't hook up the CO2 to the unit but instead use sulphur or feed it vodka or sugar (for BIO style).
I've experimented a lot with them (media and feeding) and found the following to be the highest production of nitrate reduction for my systems. I presently have the Coralife 500 reactor filled 2/3 the way up with Siporax and 1/3 with sulphur beads. I then feed a second reactor which is filled 2/3 full of Siporax and 1/3 full of Calcium reactor media. The 1st chamber has the sulphur (food) and the 2nd contains the calcium media to buffer the pH. While I used 2 chambers one could be used just as easily or the 2nd chamber could be something like a phosban reactor filled 100% with calcium reactor media.
The Siporax never needs replacing and the sulphur beads only need replacing/added to when the reactor starts to loose a little functionality (about 9 months to a year). The calcium media needs to be added to/replaced every couple of months. By using 2 chambers I never need to disturb the first chamber when adding more calcium media.
In my setup I use 2/3 full chamber of Siporax. I could have also used Matrix or just went with all Sulphur beads. As the sulphur beads start to get used up they get smaller and smaller and start to have a "clogging" effect. With only 1/3 part of sulphur this clogging effect is much less noticeable and the effluent coming out of the reactor is much more stable. The Siporax is also highly porous and can host a lot more anaerobic bacteria then the sulphur beads alone. This to me has proven to be a nice combination of media.
The Coralife calcium reactor has a pH probe port at the top of it. Instead of using a pH probe I use a ORP probe. I think having an ORP controller (or at least monitor) is critical in getting a nitrate reactor to run correctly. You want the ORP reading to be in the negative (below zero) and kept between -50 and -300. Above -50 (going towards positive) the reactor won't be processing nitrates and in fact will cause nitrates to get higher. Below -300 you will start to produce hydrogensulfide. I target -170 and have mine on a controller and AquaLifter pump. The controller will turn on/off the pump to keep the ORP right in then -150 to -200 ORP range for optimal nitrate processing.
TIP: Most ORP monitors/controllers will not read negative ORP values. Since an ORP value is nothing more then a volts reading (mV) there is a little trick you can do. Cut the probe and rewire it backwards (+ to minus, - to plus side) or pickup a couple of BNC connectors and make a "crossover" cable (what I did). With the crossover cable everything reads backwards. Plus values will show up as ZERO (or negative) but the negative ORP reading show up as positive. Now any controller can be used. You just have to remember to think "negative values". With this logic in hand, when the ORP is reading +200 (really negative 200) you want to increase the flow a bit and when the reading is +150 (really minus 150) you want to slow the flow a bit.
With a slow flow pump (and resistor to slow it down even more, IE airline valve) and an ORP controller with the crossover cable, the nitrate reactor becomes a hands off piece of equipment that doesn't need constant fiddling with. Without the use of ORP monitoring/controller you have to test the effluent for nitrates and constantly adjust flow by a couple of drops a minute to get it dialed in. This gets to be a chore after a while.
There are many styles and ways to run a nitrate reactor. The above is only a description of what I've found to work well after much experimenting and use. The best advice I can give is to read the online pdf instructions at the manufactures websites for the unit and make sure you fully understand it's operation before purchase. I only mention this because a poorly setup or run nitrate reactor can create hydrogensulfide which can crash a tank if not monitored correctly.
Note: If you run a nitrate reactor you will loose the "natural" balance of calcium and alkalinity in your system. The calcium media in the nitrate reactor will add slightly to your calcium while the nitrate reduction process itself will use up alkalinity. So be prepared to buffer your alk more and if you use a 2 part additive be prepared to deviate (not a problem in itself but something to be aware of).
Carlo
PS I had to use one of these units prior to my basement setup because of space. If you have the space I'd recommend a good refugium with macro algae and a DSB first before a nitrate reactor as it's more natural, helps with phosphates, doesn't alter your calc/alk balance and is more hands off. You can also run a fuge on alternate light cycles if needed to help stabilize your pH range.
I am using a sulfur denitrator by a company named midwestaquatic.They are very similar to the korallin the only difference is their sulfur come populated with denitrifing bacteria and John Guest valves. The unit is well made and Rick from midwest is very helpful. His company has great customer service and are willing to help with any problem you might have.
Mine has been in service for 16 weeks now. At first I had a lot of problems getting to cycle but it seem to be on it's way now. You could check out my post at midwest's forum. I use the same screen name. Midwest will even donate $50.00 to our club if you purchase 1 of their products. Check out their website.
www.midwestaquatic.com
Mine has been in service for 16 weeks now. At first I had a lot of problems getting to cycle but it seem to be on it's way now. You could check out my post at midwest's forum. I use the same screen name. Midwest will even donate $50.00 to our club if you purchase 1 of their products. Check out their website.
www.midwestaquatic.com