What is it? How does it work? Does it… work?

These are some of the frequent questions we are asked when the Korallin Bio-Denitrator is brought up in our phone conversations with our customers.

What is it?  
It is just about the most hands-free and most-effective denitrifying filter available for your aquarium. While Bio-Pellets and other forms of carbon dosing require a protein skimmer and a certain amount of phosphates to work (Redfield Ratio), the Korallin Bio-Denitrator will lower your nitrates without a protein skimmer and regardless of what your phosphate levels are. It utilizes a process call autotrophic sulfur denitrification; which was originally developed for denitrification in water treatment plants.
How does it work?
By creating an anaerobic chamber inside the Bio-Denitrator, a colony of nitrate-consuming bacteria is established on the sulfur media. The bacteria converts sulfur into sulfate and nitrates into nitrogen gas. At the same time hydrogen gas and CO2 gas are also produced: which lowers the pH of the effluent exiting the reactor. To help offset the drop in pH, a layer of calcium media is placed above the sulfur media.
The advantages of sulfur denitrification are that very little adjustment and maintenance is needed and that it does not require other pieces of equipment to work; such as a biopellet reactor or carbon-dosing needing to work in conjunction with a protein skimmer. Additionally, the sulfur media lasts a very long time (typically 1-2 years before replacement is needed), which make is very cost-effective to operate in the long run.
a few tips for installation... first remove the pump bracket and strainer.
Does it… work?
Absolutely! As long as the chamber is anaerobic, bacteria will grow and nitrate will be consumed. It is an extremely effective and proven method of lowering nitrates. Another great feature is that sulfur denitrification work in both freshwater and saltwater so it can work in a reef tank, a salt water fish-only tank or a freshwater tank.
next, install the pump bracket on the side of the pump.
Now, on to the actual Korallin Bio-Denitrator itself
Korallin reactors are heavy-duty reactors that are built to last. Going against popular trends, these German-made reactors use clear PVC instead of the conventional acrylic. Although more costly, clear PVC is more impact resistant, more durable and less prone to damage when exposed to various chemicals and everyday use and abuse.  These reactors also use high-quality Eheim pumps that efficiently recirculate the water inside these reverse-flow reactors.
the pump is secured with the white nylon nut & screw.
Once installed and running, it does take 4-6 weeks for the bacteria to fully colonize. After everything is dialed in, you simply need to briefly check it every couple of weeks to make sure the drip rates are still constant. Once every year or two, change out the media. It is just about as easy and as maintenance free as an aquarium filter can get. Additionally, if you end up not needing the Bio-Denitrator anymore, it can be fairly easily converted into a calcium reactor.
attach the inlet & outlet assemblies and you're just about done!
There are numerous ways to lower your nitrates: some require more work than others and some more effective than others. If you are looking a denitrator that work well, requires minimal effort and will last you a LONG time, the Korallin Bio-Denitrator is an excellent option!