Hi everyone, I did not see a good thread about Sulfur Dentrators, so I thought I'd post my experience.
These are used in reef tanks, but also work excellent on fresh water.
I have a 300 gallon Malawi tank that is overstocked. It has a 75 gallon wet dry filter.
I do lots of water changes, but Nitrates still hover at 10-15 ppm. I would occasionally get unexplained fish deaths, which
I suspected were due to Nitrate spikes (because my life delayed water changes). Yes, I know this is bad, and the right way
would be to reduce stocking levels, but I decided to try a denitrator.
I was worried that the ratings for the Korallin Denitrators were for reef tanks, so I was looking
for one oversized. Well, I was able to get a model S-10000 (good for 10k liters, or 2600 gallons)
I thought that would work. lol.. Turns out my fear was unfounded. If I had to do it over, would probably get a smaller one.
How they work: Water is circulated in the reactor chamber, inside the reactor is sulfur which feeds the "good bacteria"
which converts Nitrates to Nitrites to Nitrogen gas. This process also produces some acid, so crushed coral (or simliar media) is
placed in the reactor to balance the pH. Korallin says in the instructions that the amount of coral can be reduced or eliminated if
your tank is softwater or acidic.. I have no idea if this is safe or not, but that's what they say. Anyhow, water enters the reactor, is circulated
through the media to remove Nitrates and then leaves the reactor. There is quite a bit of daily adjustment until your Nitrates get down to almost zero,
but it's really not that bad. If water enters the reactor too fast (too much Nitrate), the reactor largely converts Nitrates to Nitrites. If water does
not enter the reactor fast enough, there's not enough Nitrates for the good bacteria to eat. Other bacteria which produce H2S Hydrogen Sulfide start to grow.
H2s is detoxified with oxygen,so it's not a huge concern to add a little to your tank (you will get some during the
adjustment period), but obviously, you want to keep that at a minimum.
I had a small 300 gph pump in my sump which was pumping water into filter socks. I created a "T" with ball valves on each side of the "T" to regulate the water pressure
going into the reactor. (one part of the T went to filter socks, the other went to the reactor). This is important, because if you have too much pressure in the system, the John Guest valves will leak.
I used 1/4" ice maker tubing as tubing on my Korallin reactor, which worked fine. I began by using standard 1/4" John Guest tubing valves like this.
http://www.usplastic.com/catalog/item.aspx?itemid=36899&catid=956&clickid=searchresults
However, these did not provide the quality of flow control that I needed, so I ordered a needle valve like this for the output:
http://www.usplastic.com/catalog/item.aspx?itemid=32220
The Korallin needle valve supplied works ok, but it's really easy to bump it and change your setting, so I wanted to replace it.
Once the denitrator is setup, they recommend you let the tank water flow through it to help seed the good bacteria. I let mine run for about 2 days, although
some people only recommend a couple of hours. After the initial "Seeding", you need to adjust the flow of the output down to about 1 drip per second.
Every day, you should check on the reactor. The easiest way is to use the degassing valve to fill a cup up with reactor water. Smell it. If it smells like sulfur/rotten eggs,
you probably need to up the flow. Verify by testing the output of the reactor to ensure zero nitrates and zero nitrites. I used the seachem test. An important thing to
note is that I believe the sulfur screws up the nitrate testing a little bit. So make sure you have zero nitrite and zero nitrate.. Don't just do a nitrate test, that
can be misleading! Now, the recommendations say to slowly up the flow, like to 2 drop per second next. I had an oversized reactor, so I got an explosion of good bacteria. I was
upping my flow every day.
Every day, you need to purge the reactor of Nitrogen that has been created. Otherwise the air bubbles will get into your pump. This is why a transparent Dentitrator is good.
You can look in and see if there's any air bubbles. Some of the DIY plans use PVC piping, which makes it more difficult to monitor; this is not a deal breaker though.
It's quite exciting to see all the Nitrogen gas being produced. Then you know things are working.
Eventually, you will notice that there's no more air bubbles being produced. You will probably also notice the sulfur/rotten egg smell, even when a lot of water is being pushed through
the reactor. Test your tank's nitrites and nitrates. If they are very low (below 1), you may need to remove some of the sulfur from your reactor at this time.
My reactor was oversized, so I removed about 80% of the sulfur. I kept all the crushed coral in there. My denitrator only took about 2 weeks to bring nitrites/nitrates below
1 ppm. However, it was oversized. I have read that a typical reactor takes 6-8 weeks to bring the tanks nitrates/nitrites down to near zero. Remember, test both
Nitrites and Nitrates, as the sulfur can confuse some test kits. Also, for the same reason, don't panic if you see the test kit showing Nitrites in your tank. My nitrites
were zero before the Denitrifier. I monitored the output of the reactor to ensure relatively low amounts of Nitrites were being added into my system.
Was it worth it? Heck yea it was. If you have a Monster Tank with a heavy fish load, this is one of the best investments you can make. We have no problem overspending
on oversized pumps, extra biomedia, etc.. I think this money would be better spent on Denitrators (at least in some cases). Right now, I'm pumping about
72 gallons per day through mine, so there's no problem with maintaining a near zero nitrate level (below 1). I will still do water changes, but much
less frequently and fewer gallons per change. (There was a reef guy that was doing water changes 2/week who then successfully went to 1/month after
the denitrator. Big savings in salt for him. Big savings in time for us fresh water people). Could a drip system accomplish basically the same thing?
Yea, it probably could, although with chlorine, I wouldn't want to do 72 gallons/day. Also, with my bad luck, I really didn't want to risk something
going wrong. I'm not saying drip systems are bad, I was just too scared
There are plans to DIY one,
This is a good thread on DIYing one, although I think buying a used Calcium reactor and converting it might be a better idea and more economical.
Not sure I trust the way he put this one together, but I worry a lot due to many accidents I've had. Still, very good information here.
http://reefcentral.com/forums/showthread.php?threadid=1288082
Below is a labled picture of a denitrator. I am going to use it to help explain. A pump sits on top (not pictured)
The pump inlet is a few inches below water level so that the pump does not suck in air bubbles.
Water is pumped down a tube and exits below the media. 1/4" tubing in and out takes water in and out of the reactor.
Ok, long post, but hopefully this is informative. If anyone has any questions, I will check back.
These are used in reef tanks, but also work excellent on fresh water.
I have a 300 gallon Malawi tank that is overstocked. It has a 75 gallon wet dry filter.
I do lots of water changes, but Nitrates still hover at 10-15 ppm. I would occasionally get unexplained fish deaths, which
I suspected were due to Nitrate spikes (because my life delayed water changes). Yes, I know this is bad, and the right way
would be to reduce stocking levels, but I decided to try a denitrator.
I was worried that the ratings for the Korallin Denitrators were for reef tanks, so I was looking
for one oversized. Well, I was able to get a model S-10000 (good for 10k liters, or 2600 gallons)
I thought that would work. lol.. Turns out my fear was unfounded. If I had to do it over, would probably get a smaller one.
How they work: Water is circulated in the reactor chamber, inside the reactor is sulfur which feeds the "good bacteria"
which converts Nitrates to Nitrites to Nitrogen gas. This process also produces some acid, so crushed coral (or simliar media) is
placed in the reactor to balance the pH. Korallin says in the instructions that the amount of coral can be reduced or eliminated if
your tank is softwater or acidic.. I have no idea if this is safe or not, but that's what they say. Anyhow, water enters the reactor, is circulated
through the media to remove Nitrates and then leaves the reactor. There is quite a bit of daily adjustment until your Nitrates get down to almost zero,
but it's really not that bad. If water enters the reactor too fast (too much Nitrate), the reactor largely converts Nitrates to Nitrites. If water does
not enter the reactor fast enough, there's not enough Nitrates for the good bacteria to eat. Other bacteria which produce H2S Hydrogen Sulfide start to grow.
H2s is detoxified with oxygen,so it's not a huge concern to add a little to your tank (you will get some during the
adjustment period), but obviously, you want to keep that at a minimum.
I had a small 300 gph pump in my sump which was pumping water into filter socks. I created a "T" with ball valves on each side of the "T" to regulate the water pressure
going into the reactor. (one part of the T went to filter socks, the other went to the reactor). This is important, because if you have too much pressure in the system, the John Guest valves will leak.
I used 1/4" ice maker tubing as tubing on my Korallin reactor, which worked fine. I began by using standard 1/4" John Guest tubing valves like this.
http://www.usplastic.com/catalog/item.aspx?itemid=36899&catid=956&clickid=searchresults
However, these did not provide the quality of flow control that I needed, so I ordered a needle valve like this for the output:
http://www.usplastic.com/catalog/item.aspx?itemid=32220
The Korallin needle valve supplied works ok, but it's really easy to bump it and change your setting, so I wanted to replace it.
Once the denitrator is setup, they recommend you let the tank water flow through it to help seed the good bacteria. I let mine run for about 2 days, although
some people only recommend a couple of hours. After the initial "Seeding", you need to adjust the flow of the output down to about 1 drip per second.
Every day, you should check on the reactor. The easiest way is to use the degassing valve to fill a cup up with reactor water. Smell it. If it smells like sulfur/rotten eggs,
you probably need to up the flow. Verify by testing the output of the reactor to ensure zero nitrates and zero nitrites. I used the seachem test. An important thing to
note is that I believe the sulfur screws up the nitrate testing a little bit. So make sure you have zero nitrite and zero nitrate.. Don't just do a nitrate test, that
can be misleading! Now, the recommendations say to slowly up the flow, like to 2 drop per second next. I had an oversized reactor, so I got an explosion of good bacteria. I was
upping my flow every day.
Every day, you need to purge the reactor of Nitrogen that has been created. Otherwise the air bubbles will get into your pump. This is why a transparent Dentitrator is good.
You can look in and see if there's any air bubbles. Some of the DIY plans use PVC piping, which makes it more difficult to monitor; this is not a deal breaker though.
It's quite exciting to see all the Nitrogen gas being produced. Then you know things are working.
Eventually, you will notice that there's no more air bubbles being produced. You will probably also notice the sulfur/rotten egg smell, even when a lot of water is being pushed through
the reactor. Test your tank's nitrites and nitrates. If they are very low (below 1), you may need to remove some of the sulfur from your reactor at this time.
My reactor was oversized, so I removed about 80% of the sulfur. I kept all the crushed coral in there. My denitrator only took about 2 weeks to bring nitrites/nitrates below
1 ppm. However, it was oversized. I have read that a typical reactor takes 6-8 weeks to bring the tanks nitrates/nitrites down to near zero. Remember, test both
Nitrites and Nitrates, as the sulfur can confuse some test kits. Also, for the same reason, don't panic if you see the test kit showing Nitrites in your tank. My nitrites
were zero before the Denitrifier. I monitored the output of the reactor to ensure relatively low amounts of Nitrites were being added into my system.
Was it worth it? Heck yea it was. If you have a Monster Tank with a heavy fish load, this is one of the best investments you can make. We have no problem overspending
on oversized pumps, extra biomedia, etc.. I think this money would be better spent on Denitrators (at least in some cases). Right now, I'm pumping about
72 gallons per day through mine, so there's no problem with maintaining a near zero nitrate level (below 1). I will still do water changes, but much
less frequently and fewer gallons per change. (There was a reef guy that was doing water changes 2/week who then successfully went to 1/month after
the denitrator. Big savings in salt for him. Big savings in time for us fresh water people). Could a drip system accomplish basically the same thing?
Yea, it probably could, although with chlorine, I wouldn't want to do 72 gallons/day. Also, with my bad luck, I really didn't want to risk something
going wrong. I'm not saying drip systems are bad, I was just too scared
There are plans to DIY one,
This is a good thread on DIYing one, although I think buying a used Calcium reactor and converting it might be a better idea and more economical.
Not sure I trust the way he put this one together, but I worry a lot due to many accidents I've had. Still, very good information here.
http://reefcentral.com/forums/showthread.php?threadid=1288082
Below is a labled picture of a denitrator. I am going to use it to help explain. A pump sits on top (not pictured)
The pump inlet is a few inches below water level so that the pump does not suck in air bubbles.
Water is pumped down a tube and exits below the media. 1/4" tubing in and out takes water in and out of the reactor.
Ok, long post, but hopefully this is informative. If anyone has any questions, I will check back.
