Discussing nitrate reduction

[Randy Holmes-Farley]

It is a recirculating reactor with a valve on the effluent end. You shut the output valve and recirculate the same water over and over to “cycle” the reactor. If you never open the output, then yes it would end up producing hydrogen sulfide. its an easy indicator if you start smelling eggs near the reactor. At which point you release the valve to drip. My guess is that the non-sulfur media will probably work but not be as efficiently as if you had sulfur in the reactor. But I think I will experiment with it on a QT since I already have the reactor

I understand what it is, and predict it will not be useful. If such a thing worked, people would not be using sulfur or carbon denitrators.

I discuss how all these methods work here:

Nitrate in the Reef Aquarium - REEFEDITION

Nitrate is an ion that has long dogged aquarists. It is typically formed in aquaria through the digestion of foods, and in many aquaria it builds up and can be difficult to keep at natural levels. In the past, many aquarists performed water changes with nitrate reduction as one of the primary...

www.reefedition.com

 

[Lasse]

Would some not eventually make it to the denitrification filter or do we need to avoid putting DOC into the display?

Both - if you dose in the display - some DOC will be used by heterotrophic bacteria in the main tank creating more bacteria growth, a growth that I can´t control and do not want. If I target dose - I do not need to use as much DOC as if I dose in the media. Every type of DOC have in a way different bacteria groups as main users - I prefer that the DOC released in my DT will be that type that some algae and corals release. My goal with DOC dose is only to favour denitrification not all of the other "benefits" that some companies claims. For the moment - I have probably done a miss calculation and dose to much DOC in the DSB - resulting in slimy bacteria growth. I also read very low NO3.

As you - I have a rather high flow through my bed - up to 2-300 L/H. I have 300 L water and a lot of rockworks and hidden places with low flow. If I should dose in the DT - I would risk to create anaerobic zones there I do not want them.

Sincerely Lasse

 

[CoralB]

Following

 

[GARRIGA]

Both - if you dose in the display - some DOC will be used by heterotrophic bacteria in the main tank creating more bacteria growth, a growth that I can´t control and do not want. If I target dose - I do not need to use as much DOC as if I dose in the media. Every type of DOC have in a way different bacteria groups as main users - I prefer that the DOC released in my DT will be that type that some algae and corals release. My goal with DOC dose is only to favour denitrification not all of the other "benefits" that some companies claims. For the moment - I have probably done a miss calculation and dose to much DOC in the DSB - resulting in slimy bacteria growth. I also read very low NO3.

As you - I have a rather high flow through my bed - up to 2-300 L/H. I have 300 L water and a lot of rockworks and hidden places with low flow. If I should dose in the DT - I would risk to create anaerobic zones there I do not want them.

Sincerely Lasse

I think I get it. Starving those low flow areas of carbon reduces the chance for anaerobic zones and perhaps that also minimizes chance of hydrogen sulfide otherwise why worry about anaerobic zones in the display? You have a much more developed background on bacteria and waste management than self, obviously therefore excuse the ignorance.

I'm thinking now that this target dosing as you perform reduces the affects of carbon on pH. Something I've found in my home to be of concern due to high levels of co2 that was only solved once moving away from carbon and relying on algae.

Soon as I get my test tank back up and running I'll see if I can target dose and run test against display dosing to see how much used and affect on pH. Going to run a Hydros on a 20g which seems like overkill but only way to get accurate measurements. Can split dosing with one line to display and another to canister. Looking into possibly running a DO meter with that controller as that would allow me to better meter the dosage if I can monitor the effluent. At a minimum should be educational and hopefully enlightening.

 

[Lasse]

Most of the DOC will be converted to CO2 - there you have your low pH. Its a product of how high the DOC dose is.

Sincerely Lasse

 

[Lasse]

To clarify about the Doc dosing - at least as I have understand it

Normally, it can be said that about 20% of the carbon in labile (fast) DOC will be transferred to biomass when it comes to ectothermic organisms - the rest ends up as carbon dioxide. When it comes to the extra DOC intended for the actual denitrification, it all ends up in the form of carbon dioxide but the actual denitrification is alkalinity-increasing which at least balances the pH decrease of the carbon dioxide. At least that's how I've understood it.

This means that dosing DOC decrease pH (however not alkalinity) because of more CO2 into the water. At least during no phothosynthesis. During photosynthesis - some of the CO2 will be re-converted into organic carbon as ingoing in the created biomass

Sincerely Lasse

 

[GARRIGA]

My simplistic mind breaks it down as such...

More co2 - bad
Less co2 - good

I'll try target dosing to see how that manages pH in my high co2 air tight warm climate housing.

If I can avoid using algae to manage both nutrients and co2 then that simplifies my build and maintenance. Keep it simple

 

[Mels_Reef]

My simplistic mind breaks it down as such...

More co2 - bad
Less co2 - good

I'll try target dosing to see how that manages pH in my high co2 air tight warm climate housing.

If I can avoid using algae to manage both nutrients and co2 then that simplifies my build and maintenance. Keep it simple

I may have missed it but why are you reluctant to use macro algae as a co2 and nutrient export?

 

[GARRIGA]

I may have missed it but why are you reluctant to use macro algae as a co2 and nutrient export?

I'm not but rather avoid it to reduce equipment needed and maintenance. Of sufficient quantity to make a difference requires space, lighting and plumbing plus occasional pruning along with adding trace it consumes. If I can solve my needs by dosing then that's just a simpler execution.

Been researching plants as means of filtration since the 70s and Fuge/ATS since the 80s. I want to believe but it comes at a cost and has it's pitfalls.

 

[Mels_Reef]

I'm not but rather avoid it to reduce equipment needed and maintenance. Of sufficient quantity to make a difference requires space, lighting and plumbing plus occasional pruning along with adding trace it consumes. If I can solve my needs by dosing then that's just a simpler execution.

Been researching plants as means of filtration since the 70s and Fuge/ATS since the 80s. I want to believe but it comes at a cost and has it's pitfalls.

I’m with you, and partially why I didn’t want to go that route. Plus I worry about DOC’s. My acros just never seemed to be as healthy with a refugium running, than without.

 

[GARRIGA]

I’m with you, and partially why I didn’t want to go that route. Plus I worry about DOC’s. My acros just never seemed to be as healthy with a refugium running, than without.

Was it possibly the algae pulling elements such as iron? Could be also pulling needed nutrients for the corals. Gets to be a rather complicated balancing act. Honest. Might just keep discus

 

[Mels_Reef]

Was it possibly the algae pulling elements such as iron? Could be also pulling needed nutrients for the corals. Gets to be a rather complicated balancing act. Honest. Might just keep discus

That’s kind of my feeling. The macro definitely bottomed out my iron based on ICP tests and I’m sure there is other competition going on as well.

 

[ReefGeezer]

Hey guys. I've followed along with great interest. I see that the conversation has moved toward removing nitrate... but... I thought of a different track... The OP feeds a lot of fish a lot of food. They produce a lot of nitrogen in the form of ammonia. The population of growing corals he has uses a lot of that ammonia to obtain nitrogen. In fact, there may be very little heterotrophic bacteria in his very mature system because the corals are using most of the nitrogen. It could be that anything that is added competes with the corals for nitrogen causes problems. The nitrate destroyer option may cause the same problem. So, if the nitrate remaining indicates that there is more nitrogen available than the organisms need, could the answer to the problem be as simple as adding more corals, reducing the feeding slightly, or getting a more effective skimmer? Could this answer also address the rise of phosphate to some extent?

 

[Lasse]

Hey guys. I've followed along with great interest. I see that the conversation has moved toward removing nitrate... but... I thought of a different track... The OP feeds a lot of fish a lot of food. They produce a lot of nitrogen in the form of ammonia. The population of growing corals he has uses a lot of that ammonia to obtain nitrogen. In fact, there may be very little heterotrophic bacteria in his very mature system because the corals are using most of the nitrogen. It could be that anything that is added competes with the corals for nitrogen causes problems. The nitrate destroyer option may cause the same problem. So, if the nitrate remaining indicates that there is more nitrogen available than the organisms need, could the answer to the problem be as simple as adding more corals, reducing the feeding slightly, or getting a more effective skimmer? Could this answer also address the rise of phosphate to some extent?

He has around 15 mg/L NO3 as a water in the water - its 3.38 mg/L NO3 - N and its equal to 3,38 mg/L NH4-N which is equal to 18/14*3.38 -> 4.3 mg NH4 - indeed it is not an N limited system. More corals (more N consumption/day) and/or lesser feeding (lesser N input/day) is a possible path. However - if the current skimmer not is undersized - a more effective skimmer will probably not be a solution Its very little N exporting that way - its protein - N and NH3-N that will be exported by the skimmer.

Sincerely Lasse

 

[ReefGeezer]

He has around 15 mg/L NO3 as a water in the water - its 3.38 mg/L NO3 - N and its equal to 3,38 mg/L NH4-N which is equal to 18/14*3.38 -> 4.3 mg NH4 - indeed there is not an N limited system. More corals (more N consumption/day) and/or lesser feeding (lesser N input/day) is a possible path. However - if the current skimmer not is undersized - a more effective skimmer will probably not be a solution Its very little N exporting that way - its protein - N and NH3-N that will be exported by the skimmer.

Sincerely Lasse

Thanks for the input Lasse. The reason I included a skimmer is because those Eshopps skimmers have been said to be less effective than others of the same rating. I have no experience with them though. Just a thought.

 

[GARRIGA]

After a few pages. One loses track of the origins and all too easy to go off on a tangent

 

[Mels_Reef]

Hey guys. I've followed along with great interest. I see that the conversation has moved toward removing nitrate... but... I thought of a different track... The OP feeds a lot of fish a lot of food. They produce a lot of nitrogen in the form of ammonia. The population of growing corals he has uses a lot of that ammonia to obtain nitrogen. In fact, there may be very little heterotrophic bacteria in his very mature system because the corals are using most of the nitrogen. It could be that anything that is added competes with the corals for nitrogen causes problems. The nitrate destroyer option may cause the same problem. So, if the nitrate remaining indicates that there is more nitrogen available than the organisms need, could the answer to the problem be as simple as adding more corals, reducing the feeding slightly, or getting a more effective skimmer? Could this answer also address the rise of phosphate to some extent?

Well, in case there was a misunderstanding, I don’t really feed a lot. I feed a half sheet of nori in the morning for tangs. A pinch of seachem flakes for the wrasse. In the evening I broadcast feed my protein loaded home made mix of blood worms, mysis, plankton, rotifers. The fish do well with picking up every bit of it within 3-4 minutes. I run the skimmer pretty wet and I’ve been using the same skimmer for 6 years. My nitrate is currently 13-17. That’s really not too bad for as long as the system has been running. I am just trying to slow down weekly water changes but need a way to export nutrients. PO4 is easy enough to maintain via reef roids when it’s low and lanthanum chloride when it’s high. NO3 is not as easily managed.

You mentioned getting more coral. Lol I’m going as fast as I can. And these acros grow slow lol. At the peak of my acro success I was dosing about 350ml/day of two part. Currently I am only dosing 125ml/day. So I do have a long way to go to get back to where I was. But I’m working on it.

 

[GARRIGA]

My nitrate is currently 13-17. That’s really not too bad for as long as the system has been running. I am just trying to slow down weekly water changes but need a way to export nutrients.

How high do nitrates get if you extend water changes to two weeks or four weeks? Might be you're already there and just need to provide the corals some extra time to reduce nutrients on their own.

No experience with acros but I believe WWC runs nitrates around 20-25 ppm. Richard Ross puts that to shame. Granted every tank is different but often we try solving that not needing a solution.

This mantra one must keep very narrow ranges why I might just keep discuss in the main and setup my 15 AIO that's been sitting in the garage since prior Christmas for Sticks. They seem more stressful than raising teenagers who think everything new to them must be new to the world and they are never wrong. Talk about walking narrow ranges.

 

[Aquariumaddictuk]

How high do nitrates get if you extend water changes to two weeks or four weeks? Might be you're already there and just need to provide the corals some extra time to reduce nutrients on their own.

No experience with acros but I believe WWC runs nitrates around 20-25 ppm. Richard Ross puts that to shame. Granted every tank is different but often we try solving that not needing a solution.

This mantra one must keep very narrow ranges why I might just keep discuss in the main and setup my 15 AIO that's been sitting in the garage since prior Christmas for Sticks. They seem more stressful than raising teenagers who think everything new to them must be new to the world and they are never wrong. Talk about walking narrow ranges.

I've been keeping them for years.wilds & Asians.none of those silly German ones.
There's a mantra amongst discus obsessives: "discus are not hard, they are just hard work"
100% weekly water changes with baby soft, acidic RODI & they are relatively straightforward

 

[GARRIGA]

I've been keeping them for years.wilds & Asians.none of those silly German ones.
There's a mantra amongst discus obsessives: "discus are not hard, they are just hard work"
100% weekly water changes with baby soft, acidic RODI & they are relatively straightforward

Curious why the Discus community continues to mimic Malaysian water change practices considering the advancements in filtration such as carbon dosing. No way I'm doing that