New sulfur denitrator working great!

[ReeferBud]

This is sooooo accurate! I read another thread that said it was imperative to tune the reactor. I spent $125 on a probe and stand alone meter because Apex won't read negative. I probably wasted 6 weeks fiddling with the flow trying to keep it around -170. This led to clogs, nitrite production, and large amounts of frustration. Finally I just said "screw it" and turned the flow up. Within a month my nitrates were rapidly dropping. Now, my tank is like 5ppm and effluent is 0-1ppm. My ORP readings are +220. Either my ORP probe is wrong (I don't think so because I can make drop almost instantly slowing the flow) or it isn't that important.

That’s interesting. My understanding is that the bacteria need an anoxic environment to grow and consume the nitrate, which requires a slow flow through the reactor. Otherwise, too much oxigen rich water prevents the anaerobic bacteria from doing their thing.

The apex can’t read negative ORP, but it is possible to “trick” the apex and select the ORP probe as pH when setting up the probe. This allows you to read the negative values, displayed as a pH range. For example, I know that -170 my reads as a pH of 10 and I just target that value. There are some much better explanations here on R2R in other threads.

 

[jasonrusso]

That’s interesting. My understanding is that the bacteria need an anoxic environment to grow and consume the nitrate, which requires a slow flow through the reactor. Otherwise, too much oxigen rich water prevents the anaerobic bacteria from doing their thing.

The apex can’t read negative ORP, but it is possible to “trick” the apex and select the ORP probe as pH when setting up the probe. This allows you to read the negative values, displayed as a pH range. For example, I know that -170 my reads as a pH of 10 and I just target that value. There are some much better explanations here on R2R in other threads.

Like I said, maybe the probe is malfunctioning. I finally gave up on the ORP and just started testing the effleluent.

 

[jasonrusso]

That’s interesting. My understanding is that the bacteria need an anoxic environment to grow and consume the nitrate, which requires a slow flow through the reactor. Otherwise, too much oxigen rich water prevents the anaerobic bacteria from doing their thing.

The apex can’t read negative ORP, but it is possible to “trick” the apex and select the ORP probe as pH when setting up the probe. This allows you to read the negative values, displayed as a pH range. For example, I know that -170 my reads as a pH of 10 and I just target that value. There are some much better explanations here on R2R in other threads.

Upon further inspection, I think I have a bad wire on my ORP probe. I can change the readings if I bend the wires a certain way. Either way, I am just monitoring the tank water at this point. If I see the nitrate starting to rise again, I'll check the reactor.

 

[Randy Holmes-Farley Verified Community Expert]

Does anyone know if there’s a way to estimate how much Alk is consumed by the SD? Should be possible to estimate via the chemical reaction formula, just been too long for me. Maybe @Randy Holmes-Farley can help ;Bookworm

Someone posted my calculation just above your question.

Consumption of 10 ppm nitrate adds 0.1 mole/l of acid, or 0.1 meq/l. That’s about 0.3 dKH.

That’s the lower limit. If aerobic bacteria can consume the sulfur, they will reduce alk and not use nitrate.

 

[ReeferBud]

Someone posted my calculation just above your question.

Consumption of 10 ppm nitrate adds 0.1 mole/l of acid, or 0.1 meq/l. That’s about 0.3 dKH.

That’s the lower limit. If aerobic bacteria can consume the sulfur, they will reduce alk and not use nitrate.

Thanks @Randy Holmes-Farley

I was the one who posted your formula but those calculations were about estimating the amount of Ca produced. Your calculations above is what I was looking for, which is how much Alk is consumed.

So if the difference between the input and the output of the SD is 10 ppm of NO3, that basically means that the SD is consuming 5.3 ppm of Alk (0.3 dKH). If I then use the BRS Alk calculator, using the SD throughput of 115 l/day, I’d need to add 0.9g/day of sodium bicarbonate to counter the Alk consumption of the SD.

Am I going about calculating this the right way? Thanks for your help!

 

[Randy Holmes-Farley Verified Community Expert]

That sounds like the right calculation. [emoji3]

 

[ReeferBud]

Thanks @Randy Holmes-Farley

If anyone else would like to calculate the amount of Alk being consumed by the SD, below are the calculations I used. The reason this is important is because over time, an imbalance of Ca and Alk will develop, since the SD consumes more Alk than the Ca it generates (assuming one is using calcium carbonate in the top part of the reactor and the effect is minimal). I've noticed this in my own system and have add to adjust to add more Alk than Ca. For example,
- If using a Ca Rx, since equal proportions of Alk and Ca are added to the aquarium, one will need to dose additional Alk to maintain the correct balance. Otherwise, if mostly testing and controlling Alk, which most probably do, Ca will drift towards higher levels than desired.
- If using a 2 part method, instead of dosing the same amount of Alk and Ca, one will need to compensate for the SD Alk consumption and dose more Alk than Ca

Here are the calculations:
1) Calculate Alk consumed by SD:

5.3 ppm Alk / 10 ppm NO3 x [difference between inlet and outlet of SD] ppm NO3 = X ppm Alk consumed by SD

The first term is simply the Alk/NO3 relationship shared by Randy and to calculate the 2nd term, just test NO3 of our aquarium water (in) and the outlet of the SD.

2) Calculate the throughout of the SD

Since we calculated a concentration of Alk in Step 1, to determine how much Alk is being consumed per day in our system, we must understand the throughput (flow) through the SD reactor. Just use a graduated cylinder and calculate the throughput in ml/min and multiply by 1.44 to get liters/day --> Y liters/day

3) Calculate how much Sodium Bicarbonate to compensate for SD Alk consumption

Go to the BRS Alk calculator and simply calculate how many grams of Sodium Bicarbonate need to be added per day to compensate for the SD Alk consumption. In the calculator, use the following inputs:
Volume = throughput of SD [Y] liters
Current Alk level = 0 ppm
Desired Alk level = [X] ppm

Result = Z grams of Sodium Bicarbonate

The result will give you the grams of Sodium Bicarbonate that you need to add to your system to compensate for the SD consumption. You can then adjust your programing regimen to accurate keep your parameters in balance.

Thoughts/Conclusion:
- We know that SDs aren't a very popular option in the hobby as most consider too complicated (ok, maybe they're a bit complicated). However, they work and by understanding them correctly, one can achieve good results and keep NO3 under control.
- If the Alk/Ca could be considered a "downside" to running a SD, I would personally consider it minimal. For example, I'm running an Aquamaxx TS-3, which is their largest unit on a 450 gal mixed reef. Using the calculations above, I'll need to add 1 gram of Sodium Bicarbonate per day to compensate for the SD Alk consumption. Using the BRS Sodium Bicarbonate ($22 for 7 lbs), that comes out to $0.20 per month, so basically negligible.

Hope this helps and just wanted to document for future reference. In case anyone finds any calc issues or has additional thoughts, please share

 

[Clydester]

Thanks @Randy Holmes-Farley

If anyone else would like to calculate the amount of Alk being consumed by the SD, below are the calculations I used. The reason this is important is because over time, an imbalance of Ca and Alk will develop, since the SD consumes more Alk than the Ca it generates (assuming one is using calcium carbonate in the top part of the reactor and the effect is minimal). I've noticed this in my own system and have add to adjust to add more Alk than Ca. For example,
- If using a Ca Rx, since equal proportions of Alk and Ca are added to the aquarium, one will need to dose additional Alk to maintain the correct balance. Otherwise, if mostly testing and controlling Alk, which most probably do, Ca will drift towards higher levels than desired.
- If using a 2 part method, instead of dosing the same amount of Alk and Ca, one will need to compensate for the SD Alk consumption and dose more Alk than Ca

Here are the calculations:
1) Calculate Alk consumed by SD:

5.3 ppm Alk / 10 ppm NO3 x [difference between inlet and outlet of SD] ppm NO3 = X ppm Alk consumed by SD

The first term is simply the Alk/NO3 relationship shared by Randy and to calculate the 2nd term, just test NO3 of our aquarium water (in) and the outlet of the SD.

2) Calculate the throughout of the SD

Since we calculated a concentration of Alk in Step 1, to determine how much Alk is being consumed per day in our system, we must understand the throughput (flow) through the SD reactor. Just use a graduated cylinder and calculate the throughput in ml/min and multiply by 1.44 to get liters/day --> Y liters/day

3) Calculate how much Sodium Bicarbonate to compensate for SD Alk consumption

Go to the BRS Alk calculator and simply calculate how many grams of Sodium Bicarbonate need to be added per day to compensate for the SD Alk consumption. In the calculator, use the following inputs:
Volume = throughput of SD [Y] liters
Current Alk level = 0 ppm
Desired Alk level = [X] ppm

Result = Z grams of Sodium Bicarbonate

The result will give you the grams of Sodium Bicarbonate that you need to add to your system to compensate for the SD consumption. You can then adjust your programing regimen to accurate keep your parameters in balance.

Thoughts/Conclusion:
- We know that SDs aren't a very popular option in the hobby as most consider too complicated (ok, maybe they're a bit complicated). However, they work and by understanding them correctly, one can achieve good results and keep NO3 under control.
- If the Alk/Ca could be considered a "downside" to running a SD, I would personally consider it minimal. For example, I'm running an Aquamaxx TS-3, which is their largest unit on a 450 gal mixed reef. Using the calculations above, I'll need to add 1 gram of Sodium Bicarbonate per day to compensate for the SD Alk consumption. Using the BRS Sodium Bicarbonate ($22 for 7 lbs), that comes out to $0.20 per month, so basically negligible.

Hope this helps and just wanted to document for future reference. In case anyone finds any calc issues or has additional thoughts, please share

Thanks @Randy Holmes-Farley

If anyone else would like to calculate the amount of Alk being consumed by the SD, below are the calculations I used. The reason this is important is because over time, an imbalance of Ca and Alk will develop, since the SD consumes more Alk than the Ca it generates (assuming one is using calcium carbonate in the top part of the reactor and the effect is minimal). I've noticed this in my own system and have add to adjust to add more Alk than Ca. For example,
- If using a Ca Rx, since equal proportions of Alk and Ca are added to the aquarium, one will need to dose additional Alk to maintain the correct balance. Otherwise, if mostly testing and controlling Alk, which most probably do, Ca will drift towards higher levels than desired.
- If using a 2 part method, instead of dosing the same amount of Alk and Ca, one will need to compensate for the SD Alk consumption and dose more Alk than Ca

Here are the calculations:
1) Calculate Alk consumed by SD:

5.3 ppm Alk / 10 ppm NO3 x [difference between inlet and outlet of SD] ppm NO3 = X ppm Alk consumed by SD

The first term is simply the Alk/NO3 relationship shared by Randy and to calculate the 2nd term, just test NO3 of our aquarium water (in) and the outlet of the SD.

2) Calculate the throughout of the SD

Since we calculated a concentration of Alk in Step 1, to determine how much Alk is being consumed per day in our system, we must understand the throughput (flow) through the SD reactor. Just use a graduated cylinder and calculate the throughput in ml/min and multiply by 1.44 to get liters/day --> Y liters/day

3) Calculate how much Sodium Bicarbonate to compensate for SD Alk consumption

Go to the BRS Alk calculator and simply calculate how many grams of Sodium Bicarbonate need to be added per day to compensate for the SD Alk consumption. In the calculator, use the following inputs:
Volume = throughput of SD [Y] liters
Current Alk level = 0 ppm
Desired Alk level = [X] ppm

Result = Z grams of Sodium Bicarbonate

The result will give you the grams of Sodium Bicarbonate that you need to add to your system to compensate for the SD consumption. You can then adjust your programing regimen to accurate keep your parameters in balance.

Thoughts/Conclusion:
- We know that SDs aren't a very popular option in the hobby as most consider too complicated (ok, maybe they're a bit complicated). However, they work and by understanding them correctly, one can achieve good results and keep NO3 under control.
- If the Alk/Ca could be considered a "downside" to running a SD, I would personally consider it minimal. For example, I'm running an Aquamaxx TS-3, which is their largest unit on a 450 gal mixed reef. Using the calculations above, I'll need to add 1 gram of Sodium Bicarbonate per day to compensate for the SD Alk consumption. Using the BRS Sodium Bicarbonate ($22 for 7 lbs), that comes out to $0.20 per month, so basically negligible.

Hope this helps and just wanted to document for future reference. In case anyone finds any calc issues or has additional thoughts, please share

Thanks so much for this. I'm having this issue. Problem is, I'm using Kalk in my top off water to raise PH and of course, this is also adding calcium. Since B-Ionic calcium contains trace elements as well, I'm concerned about lowering it's addition. My Calcium is currently at 700ppm. Everything else is fine. Tank is doing great. I'll back off on Calcium addition and see how much I can get it to drop over time.

 

[ReeferBud]

Thanks so much for this. I'm having this issue. Problem is, I'm using Kalk in my top off water to raise PH and of course, this is also adding calcium. Since B-Ionic calcium contains trace elements as well, I'm concerned about lowering it's addition. My Calcium is currently at 700ppm. Everything else is fine. Tank is doing great. I'll back off on Calcium addition and see how much I can get it to drop over time.

Glad it was useful

I’ve been able to maintain the correct balance in my tank since understanding this relationship. I test Ca every 2-4 weeks and seems to be good enough.

700 ppm of Ca seems very high. Not sure I’ve ever seen Ca that high before but if everything is ok in your tank, I’d just back off dosing Ca as you mentioned for a while and monitor to figure out when to start dosing again.

Cheers

 

[Clydester]

Glad it was useful

I’ve been able to maintain the correct balance in my tank since understanding this relationship. I test Ca every 2-4 weeks and seems to be good enough.

700 ppm of Ca seems very high. Not sure I’ve ever seen Ca that high before but if everything is ok in your tank, I’d just back off dosing Ca as you mentioned for a while and monitor to figure out when to start dosing again.

Cheers

I was surprised it was that high. I got everything in balance with water changes after an ICP test, started adding Kalk for ph, and equal amounts of 2 part (not much though). The latest test was with a Trident I just calibrated. The Salifert test wouldn't go high enough - so I know it's out of whack. Thanks, again..

 

[jasonrusso]

Thanks so much for this. I'm having this issue. Problem is, I'm using Kalk in my top off water to raise PH and of course, this is also adding calcium. Since B-Ionic calcium contains trace elements as well, I'm concerned about lowering it's addition. My Calcium is currently at 700ppm. Everything else is fine. Tank is doing great. I'll back off on Calcium addition and see how much I can get it to drop over time.

This is why I dose alk and calcium separately. I like to be able to control them, especially since the SD uses so much alk. I run the effluet through a phosban filled with ARM and all that seems to do is raise calcium! My alk is around 8 and calcium is around 550.

 

[Todd1white]

Thanks @Randy Holmes-Farley

If anyone else would like to calculate the amount of Alk being consumed by the SD, below are the calculations I used. The reason this is important is because over time, an imbalance of Ca and Alk will develop, since the SD consumes more Alk than the Ca it generates (assuming one is using calcium carbonate in the top part of the reactor and the effect is minimal). I've noticed this in my own system and have add to adjust to add more Alk than Ca. For example,
- If using a Ca Rx, since equal proportions of Alk and Ca are added to the aquarium, one will need to dose additional Alk to maintain the correct balance. Otherwise, if mostly testing and controlling Alk, which most probably do, Ca will drift towards higher levels than desired.
- If using a 2 part method, instead of dosing the same amount of Alk and Ca, one will need to compensate for the SD Alk consumption and dose more Alk than Ca

Here are the calculations:
1) Calculate Alk consumed by SD:

5.3 ppm Alk / 10 ppm NO3 x [difference between inlet and outlet of SD] ppm NO3 = X ppm Alk consumed by SD

The first term is simply the Alk/NO3 relationship shared by Randy and to calculate the 2nd term, just test NO3 of our aquarium water (in) and the outlet of the SD.

2) Calculate the throughout of the SD

Since we calculated a concentration of Alk in Step 1, to determine how much Alk is being consumed per day in our system, we must understand the throughput (flow) through the SD reactor. Just use a graduated cylinder and calculate the throughput in ml/min and multiply by 1.44 to get liters/day --> Y liters/day

3) Calculate how much Sodium Bicarbonate to compensate for SD Alk consumption

Go to the BRS Alk calculator and simply calculate how many grams of Sodium Bicarbonate need to be added per day to compensate for the SD Alk consumption. In the calculator, use the following inputs:
Volume = throughput of SD [Y] liters
Current Alk level = 0 ppm
Desired Alk level = [X] ppm

Result = Z grams of Sodium Bicarbonate

The result will give you the grams of Sodium Bicarbonate that you need to add to your system to compensate for the SD consumption. You can then adjust your programing regimen to accurate keep your parameters in balance.

Thoughts/Conclusion:
- We know that SDs aren't a very popular option in the hobby as most consider too complicated (ok, maybe they're a bit complicated). However, they work and by understanding them correctly, one can achieve good results and keep NO3 under control.
- If the Alk/Ca could be considered a "downside" to running a SD, I would personally consider it minimal. For example, I'm running an Aquamaxx TS-3, which is their largest unit on a 450 gal mixed reef. Using the calculations above, I'll need to add 1 gram of Sodium Bicarbonate per day to compensate for the SD Alk consumption. Using the BRS Sodium Bicarbonate ($22 for 7 lbs), that comes out to $0.20 per month, so basically negligible.

Hope this helps and just wanted to document for future reference. In case anyone finds any calc issues or has additional thoughts, please share

So if I'm using the Red Sea Mixed Reef Recipe and dosing both Cal & Alk & mag separately, (using Trident controlled dosing) I shouldn't be concerned? As I can monitor and increase/decrease Alk on a daily basis. Correct? I just bought and setup the Korallin Bio-Dentrator, using a Kamoer continuous dosing pump. TIA

 

[ReeferBud]

So if I'm using the Red Sea Mixed Reef Recipe and dosing both Cal & Alk & mag separately, (using Trident controlled dosing) I shouldn't be concerned? As I can monitor and increase/decrease Alk on a daily basis. Correct? I just bought and setup the Korallin Bio-Dentrator, using a Kamoer continuous dosing pump. TIA

if you’re using the trident to control dosing, then it should adapt the dosing amounts to compensate for the higher Alk consumption due to the SD.

let us know how your SD experience goes.

 

[ca1ore]

I have recently setup a sulfur reactor. Been running about 3 weeks and I am gradually increasing the flow. No impact on tank NO3 yet (or alk for that matter) but I have a big sys

tem and I figure it will take time.

 

[ReeferBud]

I have recently setup a sulfur reactor. Been running about 3 weeks and I am gradually increasing the flow. No impact on tank NO3 yet (or alk for that matter) but I have a big sys

tem and I figure it will take time.

what is that in the top pic?

notice you have a probe (presumably ORP) and to keep it at -170mv, I’m needing to run 200ml/min. I started with a low flow like you but the SD has been demanding more flow to stay at the desired ORP. Interested in your experience once you get it dialed in

 

[ca1ore]

Top picture is where the effluent discharges through GAC. Thing that looks a bit like a football helmet is just so I can visually see the drop rate. I’ve been gradually increasing the effluent flow. At 31 ml/min and climbing.

 

[SeaDweller]

Anyone know if the clock resets if we open up the reactor to clean it? I had to do it as my effluent was mere drips. Something was clogging it, but instead of just changing the effluent line, I thought it was detritus or build up in the reactor etc.

Sadly I rinsed away all of the bacteria that I built up for months. And man it was a lot of bacterial mulm and biofilm. I rinsed all the media. Still drips. Just changed the effluent line and all is how it was- streaming now.

I’m assuming I have no anaerobic bacteria left in there and I’m back to square one, day one. Guess i have to start testing again?

Anyone open theirs up completely to clean the reactor and media and have it not skip a beat upon reinstallation?

 

[ca1ore]

5 weeks in an up to 92 ml/min, though ORP at -64 only. Nitrate is unmeasurable on the effluent. I wonder if I should open it up and disregard the ORP number? Haven't seen a particularly significant affect on alkalinity yet. Maybe another reason to open it up. FWIW, I only get hydriogen sulfide smell when ORP drops below -225 (or thereabouts).

 

[ca1ore]

Already seeing reduction in system nitrate. Up to about 125 ml/ml, or thereabouts.

 

[Feet4Fish]

Your unit is one from Bill Wann correct. I know is workmanship is impeccable which I am sure that factored into your decision. Was it also due to the size of your system?