Sulfur Denitrator questions.

[14 foot reef]

Correct, if your water is too stagnant the ORP will drop too low and the reactor will start to produce hydrogen sulfide and smell like rotten eggs. You don't want that to happen. If it does happen, it's not the end of the world. Just turn the flow up to raise the ORP.
Apex does not report negative orp values. It'll drop to zero and then stay at zero. Even when it's negative. You have to reverse the polarity on the orp probe to get a negative number but you also have to remember it's going to look like a positive number. I have a whole write up on this on apex form here My negative orp for Apex instructions.
Your numbers are likely correct and will keep falling but you will need to reverse the polarity to keep going down this rabbit hole.

Great info, I am 1 week into this and did not realize the Apex won't read negative. I'm not running a probe, but will at some time and do as you say, reverse the polarity. Thank you

 

[MikeTheNewbie]

OK, perfect. 2 Days in you wont see a drop in ORP
what is your ml per minute on effluent ?

Right now is set to 1ml/min using a Kamoer pump on a Reef Octopus CR3000 Dual 7inch Chamber calcium reactor. It's recirculating with a Varios4 at the lowest speed. That thing is big but I only used 1L or sulfur. The probe is on the first chamber along with the sulfur.
The other chamber has a lot of reborn media.

 

[14 foot reef]

Right now is set to 1ml/min using a Kamoer pump on a Reef Octopus CR3000 Dual 7inch Chamber calcium reactor. It's recirculating with a Varios4 at the lowest speed. That thing is big but I only used 1L or sulfur. The probe is on the first chamber along with the sulfur.
The other chamber has a lot of reborn media.

Day 3 I started seeing 0.00 out of my reactor, i moved to 20ml per minute, Still zero, then day 5 moved to 40 ml per minute, then day 6 moved to 60ml per minute. so today, day 6, reading .3 at the effluent at 60 ml per minute

 

[Rst]

I tried to find the sweet spot where the flow through the reactor kept the -250 ORP average that I was shooting for. Why -250? Because I read in an article on waste water treatment that the bacteria likes that zone, so I ran with it. It works for me.
I am keeping the reactor anoxic without going stagnant. I use a large amount of sulfur media double or triple what I need for the size of my system. The effluent is always zero nitrate even if I were to run it at 200 mL a minute. The bacteria population manages itself based on the nutrients that it can receive from input.
2 weeks ago my nitrates were 5.9 so I fed a little bit less. I didn't touch the reactor this week. My nitrites are 3.1 I just test regularly and adjust feeding. (I feed very heavy most of the time)
The bacteria colony is limited by how much water you feed it. So for me, 30 ml keeps it in that zone where the bacteria population can ramp up or ramp down quickly to adjust to the current level of nitrate.
I'm not claiming to know everything there is to know about the science behind everything but I've been using a sulfur denitrator for 10 years and it's fantastic when you get it dialed in.

30 ml a minute keeps my system from cycling on and off a lot. I would like it to run continuously and still be negative. 250 millivolts orp. 30 ml per minute gets me very close to that continuous run time on the feed pump.

Thanks for the kudos on my build. I need to give it some updates.

Hi Paul, I was hoping that you wouldn’t mind giving me a little more advise. Below is the results of the first 12 hours of operating using your method. Note due to the Apex controller limitations I am forced to set the orp probe to measure in pH units (Apex won’t allow negative orp values)



RESULTS:

Kameor pump Flow set at 20ml/min; Actual Flow measured at 14ml/min

Setpts 10.7pH (-215mv) to 10.99pH (-229mv) Apex won’t allow setting pH >10.99pH

Over/Under pH actual swings: 10.7pH (-215mv) – 11.2pH (-244mv)

Typical average ON time: 47mins; Typical average OFF time: 11mins



If I understand your advice, I should set this up so that the flow pump stays ON as long as possible. I initially tried setting the flow Setpt at 30ml/min which results in a actual measured flow of 20.6ml/mn. But this flow setting resulted in average ON/OFF times of 17mins OFF and 18mins ON. So I reduced the flow Setpt to 20ml/min which resulted in improved ON/OFF times as noted in my results above.

If I set my flow much lower, I am afraid that the my orp will override my orp setpts and go completely more negative towards negative 400mv thus losing all control.

Any advice will be greatly appreciated. For example, if I triple my existing Sulfur quantity in my reactor should that greatly increase my ON times and reduce my OFF times?

 

[MikeTheNewbie]

Hi Paul, I was hoping that you wouldn’t mind giving me a little more advise. Below is the results of the first 12 hours of operating using your method. Note due to the Apex controller limitations I am forced to set the orp probe to measure in pH units (Apex won’t allow negative orp values)



RESULTS:

Kameor pump Flow set at 20ml/min; Actual Flow measured at 14ml/min

Setpts 10.7pH (-215mv) to 10.99pH (-229mv) Apex won’t allow setting pH >10.99pH

Over/Under pH actual swings: 10.7pH (-215mv) – 11.2pH (-244mv)

Typical average ON time: 47mins; Typical average OFF time: 11mins



If I understand your advice, I should set this up so that the flow pump stays ON as long as possible. I initially tried setting the flow Setpt at 30ml/min which results in a actual measured flow of 20.6ml/mn. But this flow setting resulted in average ON/OFF times of 17mins OFF and 18mins ON. So I reduced the flow Setpt to 20ml/min which resulted in improved ON/OFF times as noted in my results above.

If I set my flow much lower, I am afraid that the my orp will override my orp setpts and go completely more negative towards negative 400mv thus losing all control.

Any advice will be greatly appreciated. For example, if I triple my existing Sulfur quantity in my reactor should that greatly increase my ON times and reduce my OFF times?

Hi Rst, I think you just answered my question about whether or not the apex would display negative values for ORP. Do you have more details about it? How did you figure that out?

I had a feeling it would have some weird hard coded limitation like they do with PH where you can't set an alarm for any value above 10.9. Sometimes I'm amazed at Neptune and some other times I'm like, seriously, what were they thinking?

In any case it seems like you are using Neptune DOS. I was planning to do that to and spent some time figuring out the volumes that would have the least amount of pump idle time. Here is the table in case it helps:

Neptune DOS Info
Dosing Rates: 7, 12, 25, 60, 125 or 250 ml/min
Dose Interval should be at least 3x the time it takes to deliver 1 dose.

Max volume per rate:
Rate (ml/min)Max Daily Volume
250119,916 ml / day (4.99 L / hour) and uses 130 doses of 922.4ml every 11 minutes.
12559,958 ml / day (2.49 L / hour) and uses 130 doses of 461.2 ml every 11 minutes
6028,780 ml / day ( 1.199 L / hour) and uses 110 doses of 261.6 ml every 13 minutes
2511,991 ml / day ( 0.5 L / hour) and uses 130 doses of 92.2ml every 11 minutes
125,756 ml / day ( 0.24 L / hour) and uses 110 doses of 52.3 ml every 13 minutes
73,357 ml / day ( 0.14 L / hour) and uses 130 doses of 25.8 ml every 11 minutes

Accepts max of 119,916 ml / day (4.99 L / hour) and uses 130 doses of 922.4ml at 250 mL/min every 11 minutes.

 

[Rst]

Hi Rst, I think you just answered my question about whether or not the apex would display negative values for ORP. Do you have more details about it? How did you figure that out?

It is a well known fact the when using a ORP probe, it won't display any negative orp values. Very annoying. One workaround can be found on the Neptune Forum Gear under AquaBus Modules, Probes, and Breakout Boxes. Look for a thread "Question: Negative ORP Reading dated Jan25,2017". A second workaround is the route I took, attach you ORP probe to apex module, then for to Apex "Inputs" for the probe and change it to PH2. Now all negative orp values measured will be displayed as a pH >7. All positive orp values measured will be displayed as <7. See my post above for the conversion table to convert pH to ORP values. It is exactly equivalent.

I had a feeling it would have some weird hard coded limitation like they do with PH where you can't set an alarm for any value above 10.9. Sometimes I'm amazed at Neptune and some other times I'm like, seriously, what were they thinking?

Yes the maximum pH that can be used in Apex system is 10.99pH

In any case it seems like you are using Neptune DOS. I was planning to do that to and spent some time figuring out the volumes that would have the least amount of pump idle time. Here is the table in case it helps:

Neptune DOS Info
Dosing Rates: 7, 12, 25, 60, 125 or 250 ml/min
Dose Interval should be at least 3x the time it takes to deliver 1 dose.

Max volume per rate:
Rate (ml/min)Max Daily Volume
250119,916 ml / day (4.99 L / hour) and uses 130 doses of 922.4ml every 11 minutes.
12559,958 ml / day (2.49 L / hour) and uses 130 doses of 461.2 ml every 11 minutes
6028,780 ml / day ( 1.199 L / hour) and uses 110 doses of 261.6 ml every 13 minutes
2511,991 ml / day ( 0.5 L / hour) and uses 130 doses of 92.2ml every 11 minutes
125,756 ml / day ( 0.24 L / hour) and uses 110 doses of 52.3 ml every 13 minutes
73,357 ml / day ( 0.14 L / hour) and uses 130 doses of 25.8 ml every 11 minutes

Accepts max of 119,916 ml / day (4.99 L / hour) and uses 130 doses of 922.4ml at 250 mL/min every 11 minutes.

I do not use a DOS to control the flow rate on my Sulfur reactor. Instead I use the Kameor FX-STP pump and simply set it to the ml/min I want. Note that it pulls the effluent thru the reactor at the reactor's output.

Hope that helps, Ron

 

[MikeTheNewbie]

Hi thanks everyone for sharing recommendations and experiences. This is a very helpful thread!

I'm going to cut the ORP probe and reverse polarity so I can see the values on the Apex dashboard more easily.
I imagine when doing the reverse polarity ORP, any positive values will be displayed as 0 so maybe I'll just wait untill I actually need to read negatives.


About controllable pumps, it is probably too late for me as I'm already using a Kamoer FX-STP2 and have a spare coming in but there is one on Amazon that looks to be 0-10V controllable. I wonder if Apex could be setup to read the ORP and adjust the flow on that pump.

Here is the link
Kamoer UIP WIFI E affordable intelligent high flow peristaltic pump stepper motor 100V-240VAC adjustable dosing pump 0.5-1500ml/min touch screen control https://a.co/d/6qkF3Gu

 

[MikeTheNewbie]

Changed my mind, and will go with RST's recommendation of setting it up the ORP probe in as a pH probe in Apex, that way I can have a larger range that covers positive and negative values. Its a linear relationship ORP (mV) = -58*pH+406.
As long as I remember to aim for a "pH" of 11.31 and don't get higher than 12.17 I should be good.
Thanks again for the help!

 

[14 foot reef]

You guys really are making this seem so difficult and making me second guess my method.
What's wrong with running your effluent to test around 1 ppm of nitrate and be done with it ?

Am I missing something ?
Reading .1 today speeding up Kamoer Pump to 80 ml/min

 

[MikeTheNewbie]

LOL, you're totally right. I decided to try this method because it was supposed to be a set and forget. I need to remember to keep it simple :)

 

[14 foot reef]

LOL, you're totally right. I decided to try this method because it was supposed to be a set and forget. I need to remember to keep it simple :)

I'm fortunate to have a large body of water (1000 gallons) so less worried about bottoming out nitrate.
Just need to watch the sulfur gas possibilities building up in the chamber.

 

[Rst]

You guys really are making this seem so difficult and making me second guess my method.
What's wrong with running your effluent to test around 1 ppm of nitrate and be done with it ?

Am I missing something ?
Reading .1 today speeding up Kamoer Pump to 80 ml/min

Hi 14 footer, your method certainly works and that's the way I did it over the last 7 months. But my experience when trying to keep the effluent nitrate at or below 1ppm nitrate meant during certain periods, I needed to adjust the flow downwards every few day and during other periods, I needed to adjust the flow upwards every few days. Even then my effluent nitrate would sometimes soar above 5ppm or higher. Perhaps chasing 1ppm isn't required, but it is the method that brought down my tank nitrates from over 80 to now around 10ppm.

But at some point, for me, this testing and waiting 7mins, then adjusting the flow becomes tedious. And then also there as also a time when my flow needed to go higher than my FX-STP2 pump could handle which then required to remove 50% of my Sulfur out of my reactor and restart.

What if there was a way where only testing was required much less frequently? What if you never had to reduce or increase the quantity of sulfur in your reactor? What if you never have to adjust your effluent flow? See Sean Clark posts #51 & #53 and my post #52 above.

Ron

 

[14 foot reef]

Hi 14 footer, your method certainly works and that's the way I did it over the last 7 months. But my experience when trying to keep the effluent nitrate at or below 1ppm nitrate meant during certain periods, I needed to adjust the flow downwards every few day and during other periods, I needed to adjust the flow upwards every few days. Even then my effluent nitrate would sometimes soar above 5ppm or higher. Perhaps chasing 1ppm isn't required, but it is the method that brought down my tank nitrates from over 80 to now around 10ppm.

But at some point, for me, this testing and waiting 7mins, then adjusting the flow becomes tedious. And then also there as also a time when my flow needed to go higher than my FX-STP2 pump could handle which then required to remove 50% of my Sulfur out of my reactor and restart.

What if there was a way where only testing was required much less frequently? What if you never had to reduce or increase the quantity of sulfur in your reactor? What if you never have to adjust your effluent flow? See Sean Clark posts #51 & #53 and my post #52 above.

Ron

I will go back to those posts and see if I can try it

 

[Rst]

I tried to find the sweet spot where the flow through the reactor kept the -250 ORP average that I was shooting for. Why -250? Because I read in an article on waste water treatment that the bacteria likes that zone, so I ran with it. It works for me.
I am keeping the reactor anoxic without going stagnant. I use a large amount of sulfur media double or triple what I need for the size of my system. The effluent is always zero nitrate even if I were to run it at 200 mL a minute. The bacteria population manages itself based on the nutrients that it can receive from input.

Sean, I just noticed why you didn't respond to my post #64. I tried to correct this just now but its not possible. I am extremely sorry & embarrassed for referring to you as Paul. Hope you can forgive one of my many senior moments.:)

 

[Sean Clark]

Hi Paul, I was hoping that you wouldn’t mind giving me a little more advise. Below is the results of the first 12 hours of operating using your method. Note due to the Apex controller limitations I am forced to set the orp probe to measure in pH units (Apex won’t allow negative orp values)



RESULTS:

Kameor pump Flow set at 20ml/min; Actual Flow measured at 14ml/min

Setpts 10.7pH (-215mv) to 10.99pH (-229mv) Apex won’t allow setting pH >10.99pH

Over/Under pH actual swings: 10.7pH (-215mv) – 11.2pH (-244mv)

Typical average ON time: 47mins; Typical average OFF time: 11mins



If I understand your advice, I should set this up so that the flow pump stays ON as long as possible. I initially tried setting the flow Setpt at 30ml/min which results in a actual measured flow of 20.6ml/mn. But this flow setting resulted in average ON/OFF times of 17mins OFF and 18mins ON. So I reduced the flow Setpt to 20ml/min which resulted in improved ON/OFF times as noted in my results above.

If I set my flow much lower, I am afraid that the my orp will override my orp setpts and go completely more negative towards negative 400mv thus losing all control.

Any advice will be greatly appreciated. For example, if I triple my existing Sulfur quantity in my reactor should that greatly increase my ON times and reduce my OFF times?

Sorry about missing this and thanks for the bump.
I would say baby steps, take your time, try 22ml/min on the kameor then 24 and let it settle in at those set points for a day or two then check your Apex logs to see where you're settled in at for run times. Don't even worry about what your nitrate on the effluent is at this point. Try to get it at a nice, slow flow rate that keeps you anoxic. Let the bacteria population build up and do their job once they're well established. You shouldn't have to touch anything for the most part.
I use to use the fx-stp and never really calibrated it. It was more set results. The number was always just a reference and I didn't expect it to be precisely calibrated. It doesn't matter if 20 is 20 and 30 is 30 (Plus that's one less thing to have to calibrate all the time). I could get a year out of one tube on the Kamoer. I'll get 2 months on the versa tube.
As far as the nitrogen gas that builds up inside of the reactor, I pull my effluent out of the top lid of the reactor. So every time an gas bubble develops it automatically clears itself through the effluent. I don't have to touch my reactor at all and it never builds up gas anymore. This is why if you look at my picture above, you'll see that my effluent from the reactor is actually plugged with an RO fitting.

 

[14 foot reef]

Sorry about missing this and thanks for the bump.
I would say baby steps, take your time, try 22ml/min on the kameor then 24 and let it settle in at those set points for a day or two then check your Apex logs to see where you're settled in at for run times. Don't even worry about what your nitrate on the effluent is at this point. Try to get it at a nice, slow flow rate that keeps you anoxic. Let the bacteria population build up and do their job once they're well established. You shouldn't have to touch anything for the most part.
I use to use the fx-stp and never really calibrated it. It was more set results. The number was always just a reference and I didn't expect it to be precisely calibrated. It doesn't matter if 20 is 20 and 30 is 30 (Plus that's one less thing to have to calibrate all the time). I could get a year out of one tube on the Kamoer. I'll get 2 months on the versa tube.
As far as the nitrogen gas that builds up inside of the reactor, I pull my effluent out of the top lid of the reactor. So every time an gas bubble develops it automatically clears itself through the effluent. I don't have to touch my reactor at all and it never builds up gas anymore. This is why if you look at my picture above, you'll see that my effluent from the reactor is actually plugged with an RO fitting.

Sean can you repost the pic of where you are pulling effluent from ?

 

[Sean Clark]

Sean can you repost the pic of where you are pulling effluent from ?

The white tube in my hand is my effluent. Normally it would come from the valve just to the right.

 

[14 foot reef]

The white tube in my hand is my effluent. Normally it would come from the valve just to the right.

And you pull through the reactor, not push through correct ? What is the advantage there ?

 

[Sean Clark]

And you pull through the reactor, not push through correct ? What is the advantage there ?

I push through. No real preference. I don't see any advantage either way.

When I first got it I used a gravity feed only and that required it to be pushed through not pulled through so I just stuck with it that way when I added a pump.

 

[14 foot reef]

@Sean Clark
I have a manual bleed off circled in red finger on. Circled in green is the effluent coming out that also auto bleeds gas.
See photo