CamGG
Community Member
The full story is below. The short story is I’ve become obsessed with trying to get a sulfur denitrator to work. I’ve started injecting vinegar into the reactor. I’m posting this because I would like to hear from others what they think the chemistry/ biochemistry is occurring here and the things I could try.
The tank is a 90gallon with a 15-gallon sump. Three fish, two clowns, and a tang. A handful of softie corals. Nitrates are always around 20 or higher. My corals hate water changes even though I match the salinity, alkalinity, calcium, pH, and temperature perfectly. This is the reason I’m trying to use a denitrator.
The chemical reaction for thiobacillus can be found here
https://www.sciencedirect.com/topic...-molecular-biology/thiobacillus-denitrificans
Here's an article discussing how Thiobacillus Denitrificans uses CO2 as its carbon source.
https://pubmed.ncbi.nlm.nih.gov/161...cies of,carbon source under anoxic conditions.
There are hundreds of articles on this. These bacteria can get carbon in different pathways. They can oxidize many different sulfur compounds as well as various metals including iron. I’ve found articles claiming that thiobacillus is dependent on another bacterium. I don’t think anyone fully understands how these denitrators work.
The Fully Story
I converted a Korallin C1502 calcium reactor into a sulfur denitrator a little over a year ago. I filled the reactor with korallin sulfur and limestone. I started off with a drop every two seconds and had no success after months. I went down to a drop every 4 seconds and began to see nitrites in the effluent.
This never changed though. This went on for months. I eventually took out some limestone and added some Fluval bio-media to try to make more surface area for bacteria. This had no effect on the reactor.
The only way 0 nitrate/nitrite water would come out of the reactor is if it were as slow as a drop every 10-20 seconds. The next thing I attempted was to peal the korallin sticker and glue off and submerge the reactor. The water level in the sump covered about ¾ of the reactor. I don’t believe these are meant to be submerged but the bolts were not in the water so it did not concern me. I submerged it to try to bring the temperature up for the biological processes. This had no effect.
In the course of this whole time, I looked at dozens of scientific papers regarding thiobacillus denitirificans as there has been extensive research for water treatment plants. I also looked for other people who could never get their reactors working. There must be some reason why they work for some and not at all for others. In my case, it was obvious that the bacteria existed in the reactor but were either not growing to a large enough population to treat the water. Something was limiting their growth.
I eventually stumbled on to a scientific paper discussing the carbon sources used by Thiobacillus and their primary is through the reduction of carbon dioxide. Maybe it’s possible that some tanks do not have a high enough CO2 concentration to support these reactors. I have a protein skimmer rated for 210g on a 90-gallon tank. I then attempted injecting 0.8ml of vodka into the feed pump. A few hours later the effluent was nitrate/nitrite-free.
Going this route, I changed out some plumbing parts to be able to inject straight into the reactor. Unfortunately, air entered the reactor and I had to start over again. After a few days of dosing vodka I got no results this time.
With the drip rate at one per 5 seconds, the effluent was saturated with nitrites. I read another report claiming that acetate can un-suppress the gene required for sulfur oxidation. I then attempted 5% vinegar always diluted with 10ml of clean saltwater. Five hours after the injection I got nitrate/nitrite-free water. This roughly coincides with the 4.4 hours replication rate I found for thiobacillus denitrificans(if under optimal conditions which no reef tank is). At this point, I put the drip rate to one drop per 4 seconds and waited 24 hours. The nitrites were present again so I repeated the injection of 0.5ml of vinegar diluted in saltwater. Five to six hours later the effluent was clean so I went down to two seconds. I repeated the injection but went to 0.6ml of vinegar.
The effluent became clear but a few hours later it was full of nitrites. I injected a 1-10ml vinegar-saltwater ratio into the reactor. An hour later the effluent was clear. Full of nitrites again the next morning. I think there could be a few things occurring here. Either the vinegar is going towards the production of new bacteria, to the production of thiobacillus, or this carbon source is entirely necessary for denitrification. If it were solely the replication of thiobacillus then when the vinegar dosing is stopped, the reactor should continue to work. While doing this, dozens of bubbles popped up in the reactor which I assume are nitrogen gas. To this point, the Fluval, sulfur, and limestone media look brand new still. The entire internals of the reactor looks spotless.
There is also no way for me to know what bacteria is actually in the reactor. There are dozens of denitrifying bacteria that exist.
The tank is a 90gallon with a 15-gallon sump. Three fish, two clowns, and a tang. A handful of softie corals. Nitrates are always around 20 or higher. My corals hate water changes even though I match the salinity, alkalinity, calcium, pH, and temperature perfectly. This is the reason I’m trying to use a denitrator.
The chemical reaction for thiobacillus can be found here
https://www.sciencedirect.com/topic...-molecular-biology/thiobacillus-denitrificans
Here's an article discussing how Thiobacillus Denitrificans uses CO2 as its carbon source.
https://pubmed.ncbi.nlm.nih.gov/161...cies of,carbon source under anoxic conditions.
There are hundreds of articles on this. These bacteria can get carbon in different pathways. They can oxidize many different sulfur compounds as well as various metals including iron. I’ve found articles claiming that thiobacillus is dependent on another bacterium. I don’t think anyone fully understands how these denitrators work.
The Fully Story
I converted a Korallin C1502 calcium reactor into a sulfur denitrator a little over a year ago. I filled the reactor with korallin sulfur and limestone. I started off with a drop every two seconds and had no success after months. I went down to a drop every 4 seconds and began to see nitrites in the effluent.
This never changed though. This went on for months. I eventually took out some limestone and added some Fluval bio-media to try to make more surface area for bacteria. This had no effect on the reactor.
The only way 0 nitrate/nitrite water would come out of the reactor is if it were as slow as a drop every 10-20 seconds. The next thing I attempted was to peal the korallin sticker and glue off and submerge the reactor. The water level in the sump covered about ¾ of the reactor. I don’t believe these are meant to be submerged but the bolts were not in the water so it did not concern me. I submerged it to try to bring the temperature up for the biological processes. This had no effect.
In the course of this whole time, I looked at dozens of scientific papers regarding thiobacillus denitirificans as there has been extensive research for water treatment plants. I also looked for other people who could never get their reactors working. There must be some reason why they work for some and not at all for others. In my case, it was obvious that the bacteria existed in the reactor but were either not growing to a large enough population to treat the water. Something was limiting their growth.
I eventually stumbled on to a scientific paper discussing the carbon sources used by Thiobacillus and their primary is through the reduction of carbon dioxide. Maybe it’s possible that some tanks do not have a high enough CO2 concentration to support these reactors. I have a protein skimmer rated for 210g on a 90-gallon tank. I then attempted injecting 0.8ml of vodka into the feed pump. A few hours later the effluent was nitrate/nitrite-free.
Going this route, I changed out some plumbing parts to be able to inject straight into the reactor. Unfortunately, air entered the reactor and I had to start over again. After a few days of dosing vodka I got no results this time.
With the drip rate at one per 5 seconds, the effluent was saturated with nitrites. I read another report claiming that acetate can un-suppress the gene required for sulfur oxidation. I then attempted 5% vinegar always diluted with 10ml of clean saltwater. Five hours after the injection I got nitrate/nitrite-free water. This roughly coincides with the 4.4 hours replication rate I found for thiobacillus denitrificans(if under optimal conditions which no reef tank is). At this point, I put the drip rate to one drop per 4 seconds and waited 24 hours. The nitrites were present again so I repeated the injection of 0.5ml of vinegar diluted in saltwater. Five to six hours later the effluent was clean so I went down to two seconds. I repeated the injection but went to 0.6ml of vinegar.
The effluent became clear but a few hours later it was full of nitrites. I injected a 1-10ml vinegar-saltwater ratio into the reactor. An hour later the effluent was clear. Full of nitrites again the next morning. I think there could be a few things occurring here. Either the vinegar is going towards the production of new bacteria, to the production of thiobacillus, or this carbon source is entirely necessary for denitrification. If it were solely the replication of thiobacillus then when the vinegar dosing is stopped, the reactor should continue to work. While doing this, dozens of bubbles popped up in the reactor which I assume are nitrogen gas. To this point, the Fluval, sulfur, and limestone media look brand new still. The entire internals of the reactor looks spotless.
There is also no way for me to know what bacteria is actually in the reactor. There are dozens of denitrifying bacteria that exist.
