sulfur reactor question

ReeferBill · Feb 12, 2013

Ok, so I got a korallin 1502S used, but it seems to be working well. My nitrates are very high. The denitrator has been running for about 5-6 days. The first 2-3 days there was a little amount of gas that was at the top of the reactor. I release the gas every day, but yesterday and today I have had the gas build up so much, that by the time I get home from work(about 8 hours) the gas has built up so much that the pump is sucking air. So there is a good 2-3 inches of gas at the top of the reactor. Is this normal in the cycling of this kind of reactor? Has anyone had this experience?
Thanks,
Bill

robert · Feb 12, 2013

The production of nitrogen gas means its working.

I don't know the Koralin reactor - but I wouldn't think it it should be building up a pocket of trapped gas.

Most of the time these things have an inflow which goes to the bottom of the reactor (or close to it) and an outflow which comes from the very top of the reactor - the outflow usually carries any trapped gas away with the water flowing through it. (This outflow can be fed into the skimmer where any excess N2 gas gets blown off if you want)

The fact that your building up gas suggests that the outflow tube is drawing too deep down in the reactor - or maybe even that the flow through the chamber is backwards.

ReeferBill · Feb 13, 2013

Yeah, it seems to be producing the gas from the media. My reactor has a valve on the top that I open and release the air, which leads me to believe that it is there for a purpose, but it would be nice if it vented through the outflow. I will check that out.
The flow through the chamber is not backwards though, because I can see media on the bottom circulating with the water flow. Just came down to a large pocket of air again. I have to figure this out...

ReeferBill · Feb 13, 2013

Ok, so I looked at the reactor and the outflow actually looks like it comes from the bottom of the reactor. Check out the picture in the link I sent and it shows that the outflow comes from the grey tube at the bottom. At this point I have put another tubing onto the venting valve so the gas does not build up and run my pump dry. But I am looking for any opinions on this right now.
Korallin BioDenitrator w/ Eheim 1048 Pump

robert · Feb 14, 2013

I found these - maybe of some help.

http://www.f3images.com/IMD/filters_korallin_biodenitrator_installation_diagram_1.gif
http://www.f3images.com/IMD/filters_korallin_biodenitrator_installation_diagram_2.gif

I also see where others have had the same problem: New Nitrate Removal Korallin Sulfur-Based BioDenitrator - Page 14 - Reef Central Online Community

I've built many of these of various sizes and designs - if the gas is interfering with either the re-circulation or flow through - it would be an issue.
There is no reason I can see to draw the effluent from the bottom of the chamber.

gettaReef · Jul 8, 2015

I just stumbled across this thread as I'm setting up a Korallin BioDenitrator. How do (or did) you like the reactor? Did it work well? What did you do to solve the gas buildup problem? Any other issues? Thanks

robert · Jul 10, 2015

I've not used a Korallin...but I've used sulphur denitrators extensively. They work amazingly and can run pretty much unattended for a year or more well when set up and tuned properly.

The seperation of the sulphur from the coral stone in the Korallin is not needed (although it looks cool) and actually limits the phosphate removal potential of the reactor. (yes sulphur denitrators can remove phosphate too).

Gas should never accumulate if the outflow is taken from the very top of the reaction chamber.

The biggest issue is the aqualifter pump...its no good...(sorry to anyone who thinks otherwise). The 1/4 " tubing which is used clogs with bacterial film and you end up with a smelly mess. Use a higher flow, larger return tubing and a tighter mix of media to aviod the problems.

The only other caution is to watch your alk levels - its my experience that the suphur denitrator can be a heavy drain on the alk with perhaps a plus on the calcium side. Watch you levels as it comes on line and adjust as needed.

Randy Holmes-Farley · Jul 10, 2015

robert said:
The seperation of the sulphur from the coral stone in the Korallin is not needed (although it looks cool) and actually limits the phosphate removal potential of the reactor. (yes sulphur denitrators can remove phosphate too).
.

Why do you think separating the media impacts phosphate?

robert · Jul 10, 2015

As I understand it, the autotrophic dentitrifying bacteria sequester phospate as struvite (MAP although there is some question on exact form as I remember) in packed bed reactors used in waste water treatment.

Aparently the proximity of the suphur to the stone was one factor which affected the efficiency of the reactors. (Prehaps the proximity of the fuel source to the micro-environment created by the bacterial films) and a fairly high phosphate removal rate (along with denitrification) can be achieved.

I have the full texts of a couple of the studies on another computer I could probably dig up if your interested. These cites come from the field of waster water treatment - but operate at the temps / pH and alk we seen in our aquariums.

gettaReef · Jul 10, 2015

Thank you for the response, great info. Unfortunately I will be using the aqualifter for the Korallin unit at first as that is what I have. Do you have any pumps you could recommend to use instead of the aqualifter? My system only has high nitrates, phosphates are close to zero so due to this I plan to run the media in the chamber as korallin suggests, but it is good to know that if phosphates become a issue in the future that mixing the media can help.
Other than finding a suitable pump to flow through the unit (which should take care of having to adjust the drip rate from increasing or decreasing due to the inefficient aqualifter), my other main concern is the gas buildup that may form. So you advise packing the media as tight as possible to help with this? I have also heard some people advise raising the output tube so that it is higher or at the same height as the top of the reactor will help eliminate gas buildup. Also, would you advise I use the top output tubing as my main output (which is typically used to let air/gas out of the unit) instead of the normal outflow piping? I believe I have heard of this helping eliminate gas buildup also.
As for Alk increase, I am planning on observing that closely and dosing accordingly.
Thank you again for your advice and help

Randy Holmes-Farley · Jul 10, 2015

robert said:
As I understand it, the autotrophic dentitrifying bacteria sequester phospate as struvite (MAP although there is some question on exact form as I remember) in packed bed reactors used in waste water treatment.

Aparently the proximity of the suphur to the stone was one factor which affected the efficiency of the reactors. (Prehaps the proximity of the fuel source to the micro-environment created by the bacterial films) and a fairly high phosphate removal rate (along with denitrification) can be achieved.

I have the full texts of a couple of the studies on another computer I could probably dig up if your interested. These cites come from the field of waster water treatment - but operate at the temps / pH and alk we seen in our aquariums.

I would be interested to see how it might relate to our systems. Thanks.

robert · Jul 10, 2015

@gettaReef

"Unfortunately I will be using the aqualifter" => I did too for a long time. Most issues you will encounter will be due to the aqualifter...I eventually just put a tap on the return side of my main pump and increased the tubing size into an out of my reactor...problems solved.

"I plan to run the media in the chamber as korallin suggests" => It will work as a denitrator just fine.

"my other main concern is the gas buildup that may form. So you advise packing the media as tight as possible to help with this" => No I advise a tighter media for two reasons, first to facilitate the phosphate removal which you don't care about, and secondly to allow a higher flow through the reactor while still keeping anoxic zones in the media.

"I have also heard some people advise raising the output tube so that it is higher or at the same height as the top of the reactor will help eliminate gas buildup" => yep, but if the output is taken from the gas purge valve that should not be an issue.

"Also, would you advise I use the top output tubing as my main output" => as long as the output is 1/4 or better, definately.

"As for Alk increase, I am planning on observing that closely and dosing accordingly" => the reactor will consume alk, not increase it. Watch for a drop in Alk and a potential increase in calcium.

Good luck with it, I'm a fan of sulphur denitrification...

gettaReef · Jul 11, 2015

Haha, my bad, I definitely meant "alk decrease" as fixing it by "dosing accordingly" makes no sense (unless there is a product I don't know about that lowers Alk). Thanks again for the great advice.

Adding a tap on my return pump will be an easy way for me to run the reactor, as well as increasing the input/output of the reactor tubing size. When you did this, did your output of the reactor still output by "drips" or was it a stream? If a stream, how did you regulate it? I will start with the aqualifter but either switch to running by my return pump or get a more precise and powerful Cole Parmer pump.
Also I think I will start by using the advised output piping but if gas starts to form, which I'm sure it will, I will just switch to the top piping (aka gas purge valve) as the output.

Any other advice before I hook it up? I really appreciate your time and experience. I'm sure I will have more questions along the way, but can't wait to see the change in my system with (finally) lower nitrates. Tank is 5 years old now and I haven't been able to get lower than 40ppm nitrates for 4 years despite many efforts