New CaRx - Huge hit time system ph - Help?

[Sweet Reef Corals]

I have a 200g completely stocked wall to wall SPS system. As of Friday I was dosing a gallon of full strength Kalkwasser every 3 days as well as 300mL/day soda ash/Calcium 2 part via a DOS. This was becoming too much work so I decided to set up a GeoReefs 618 CaRx.

My normal system pH range with the old dosing was on average 7.95(overnight) to 8.45(peak photo period). I run a small fuge at night and also run a dual canister CO2 scrubber system tied to the skimmer intake 24/7.

Since setting the CaRx up Friday and gradually dialing it in while decreasing my Alk/Ca dosing, I am seeing my system take a huge hit on system ph because of the CaRx effluent. I am running the Kamoer at 28ml/minute and the reactor ph is at 6.22. I still have a little ways to go to stop 2 part dosing all together. So, I’m going to have to either increase the drip rate or lower the reactor ph more. This is only going to hit my sysyem ph even harder. You may ask, why does it matter? Well, the system was dialed in really well and balanced as far as consumption and nutrients. I was always steady at .02-.04 Phos and 5-12 NO3. With the decreased ph equalling decreased consumption by the SPS, I am seeing the nutrients rise to a level that is allowing some algae to start popping up all over the system and I can’t have that. I am OCD

So I am looking at suggestions on getting the effluent gassed off or a way to get overall better system ph when running a CaRx. Thanks!!

 

[nereefpat]

Have you used a CaRX before? See if this article helps: https://docs.google.com/document/d/1VVDp1UOhxK1by9ofK0K83q2RyArEAEYtueOuUFy4SzI/edit

I wouldn't use pH to tune it.

 

[Sweet Reef Corals]

Have you used a CaRX before? See if this article helps: https://docs.google.com/document/d/1VVDp1UOhxK1by9ofK0K83q2RyArEAEYtueOuUFy4SzI/edit

I wouldn't use pH to tune it.

Thanks, that is a very informative doc. Wish I would have found that many hours of research earlier lol. However, I’m not trying to tune the CaRx. I get all that. I am trying to get some of the CO2 out of the effluent before it goes into the system....

 

[zeronum]

Thanks, that is a very informative doc. Wish I would have found that many hours of research earlier lol. However, I’m not trying to tune the CaRx. I get all that. I am trying to get some of the CO2 out of the effluent before it goes into the system....

From what I understand a second chamber helps

 

[Sisterlimonpot]

A 2nd chamber is touted to work, but in reality, very little evidence to support that it's anecdotal at best.

My question is why not increase effluent while raising reactor pH up to 6.7-6.8?

Although that a bit presumptive of me to suggest that without knowing what media you're using.

Unless you're using aragonite I wouldn't suggest running pH lower than 6.6. Reborn, Arm dissolve around 7. Although that's still going to lower your overall tank pH, there's very little you can do besides using c02 scrubber media to raise overall tank pH, which can get very expensive.

I don't know what wall to wall corals mean... but I would increase your kamoer pump before lowering reactor pH. But if you have a heavy calcium carbonate demand, at some point lowering the reactor pH is the only option. But like I said, I'd push the effluent up to max before lowering reactor pH.

 

[PedroYoung]

You can continue to run the Kalk to counter the pH drop from the reactor, that would also lower the demand from the reactor. I’ve also seen people adding reactor effluent to the fuge which can absorb some of the CO2 (at least while the fuge light is running). I have a reactor on order and that’s my plan if pH takes too much of a hit (Kalk). I saw BRS had done some testing on second chamber effects on pH of effluent and they were negligible but I’ll prob do it anyway if the Kalk can’t offset the reactor

 

[X-37B]

Thanks, that is a very informative doc. Wish I would have found that many hours of research earlier lol. However, I’m not trying to tune the CaRx. I get all that. I am trying to get some of the CO2 out of the effluent before it goes into the system....

I drip my carx effluent into a tube filled with bones which may help.
My ph runs 7.9-8.2 which is the same as when I dosed 2 part.
Never had an issue at those ph levels.

Is your system on a ph probe and controller?
What is the current dkh of the effluent?

This what I do with my drip.
My settings are:
MLPM 48
BPM 48
Dkh onlyn14 but system is newish.

 

[Adam1985]

I think logically a second chamber or even third chamber would be your best bet. I run my effluent through two extra stages to react any remaining carbonic acid with the CaCO3 in the additional chambers. As a final tool if effluent pH is significantly lower than tank pH after the two extra stages, I optionally run the effluent into my skimmer chamber to enjoy whatever degassing that offers (skimmer air feed is piped from outside my home; I also have a CO2 scrubber to use if I ever need it, but I don’t). Skimmer is a RO 250-EXT. My system is about 220 gallons total and right now my reactor is running at pH 6.5 in the main reactor with effluent flow rate of 60 mL/min to keep alkalinity at around 8.5 dKH. is pH varies from a daily low of about 8.2 to a daily high of about 8.3-8.35. It’s running about 0.15 higher since before adding the 3rd stage (2nd degassing stage).

Media is generic old style “coral bones” exactly like old style Reborn which is collected from an island in the South China Sea, with about 10% dolomite for Mg. Luckily I can source the Reborn equivalent where I live.

My pH is not lowered vs. high pH 2 part I was using pre-CaRx and is more stable.

I haven’t measured effluent pH or alk in a long time but can if you want.

Easier said than done but my system is accomplishing this otherwise I’d see a pH drop just like you.

 

[Adam1985]

I drip my carx effluent into a tube filled with bones which may help.
My ph runs 7.9-8.2 which is the same as when I dosed 2 part.
Never had an issue at those ph levels.

Is your system on a ph probe and controller?
What is the current dkh of the effluent?

This what I do with my drip.
My settings are:
MLPM 48
BPM 48
Dkh onlyn14 but system is newish.

Different approach but concept same as mine and shows that the additional stages are the way to go if you can’t tune the reactor to perfection where zero CO2 is coming out with the effluent.

I know some people have been able to tune perfectly to use up all CO2 in the main reactor but I prefer to just keep the pH stable in the main reactor as a primary control mechanism using a pH controller with solenoid on the CO2 regulator.

 

[Dennis Cartier]

This is something that I have been pondering lately. How to get the least amount of pH drop while using a CaRx. Which correlates nicely to your situation.

What I believe is that you need to shoot for the strongest effulent possible, so you can dose as little as possible to your tank.

I will use my setup as an example of this concept. I run an AE ACR in saturation mode, pressurized to 5 psi. The pH inside my reactor is high to mid 5's.

My effulent flows out of the ACR to a powered second stage, a Geo 618 with no CO2 hooked up. Then it flows through a 2" inline cannister filled with ReMag. It finishes off the journey to the sump, passing through an aeration tower that has room air bubbled through it for 90 seconds every 15 minutes.

The pH inside the Geo is 6.10 (+/- 0.03). When it exits the aeration tower it is 6.8 - 7.2 (depending on time of day, higher at night).

My effulent tests at a steady 90 dKH. My baseline flow rate is 8 ml/min. I slow my reactor at night and boost it during peak light hours.

My tank pH over the past 24 hours (tested every 6 hours) was 8.31, 8.27, 8.37, 8.42.

I was dosing kalk, but took it offline to make my tank more tank sitter friendly (it needed to be mixed every 4 days).

I have a lot of systems in place to combat low pH. All the CaRx ones already mentioned, plus outside air to my skimmer, a skimmer pump inside my fuge barrel, an HRV system, etc.

With all that being said, my belief is that to limit the potential pH drop you can get from a CaRx is to limit the amount of effulent required to as little as possible by making it as potent as possible.

When BRS did their video testing if a secondary chamber raises pH, they found that it did not raise the pH to any degree, but greatly strengthened the effulent. So they concluded no, it doesn't raise the pH.

I think they missed the forest for the trees, because having effulent that is 50% stronger (what their test showed), would allow you to dose much less effulent, and get much less drag on your pH as a result. So even in their test, a higher tank pH would result, though they failed to point that out.

So long story short, flow your effulent over as much media as possible, preferably in a powered active stage, to get every last bit of dKh out of the CO2 used. That should give you the highest tank pH while using a CaRx.

 

[PeterC99]

Basic question - what media are you using in your Calcium reactor and what is the lowest pH reading in that reactor to get the media to dissolve?

 

[Adam1985]

I use clean coral bones and haven’t registered a
pH below 6.48 （set point 6.5).

 

[Adam1985]

This is something that I have been pondering lately. How to get the least amount of pH drop while using a CaRx. Which correlates nicely to your situation.

What I believe is that you need to shoot for the strongest effulent possible, so you can dose as little as possible to your tank.

I will use my setup as an example of this concept. I run an AE ACR in saturation mode, pressurized to 5 psi. The pH inside my reactor is high to mid 5's.

My effulent flows out of the ACR to a powered second stage, a Geo 618 with no CO2 hooked up. Then it flows through a 2" inline cannister filled with ReMag. It finishes off the journey to the sump, passing through an aeration tower that has room air bubbled through it for 90 seconds every 15 minutes.

The pH inside the Geo is 6.10 (+/- 0.03). When it exits the aeration tower it is 6.8 - 7.2 (depending on time of day, higher at night).

My effulent tests at a steady 90 dKH. My baseline flow rate is 8 ml/min. I slow my reactor at night and boost it during peak light hours.

My tank pH over the past 24 hours (tested every 6 hours) was 8.31, 8.27, 8.37, 8.42.

I was dosing kalk, but took it offline to make my tank more tank sitter friendly (it needed to be mixed every 4 days).

I have a lot of systems in place to combat low pH. All the CaRx ones already mentioned, plus outside air to my skimmer, a skimmer pump inside my fuge barrel, an HRV system, etc.

With all that being said, my belief is that to limit the potential pH drop you can get from a CaRx is to limit the amount of effulent required to as little as possible by making it as potent as possible.

When BRS did their video testing if a secondary chamber raises pH, they found that it did not raise the pH to any degree, but greatly strengthened the effulent. So they concluded no, it doesn't raise the pH.

I think they missed the forest for the trees, because having effulent that is 50% stronger (what their test showed), would allow you to dose much less effulent, and get much less drag on your pH as a result. So even in their test, a higher tank pH would result, though they failed to point that out.

So long story short, flow your effulent over as much media as possible, preferably in a powered active stage, to get every last bit of dKh out of the CO2 used. That should give you the highest tank pH while using a CaRx.

This is something that I have been pondering lately. How to get the least amount of pH drop while using a CaRx. Which correlates nicely to your situation.

What I believe is that you need to shoot for the strongest effulent possible, so you can dose as little as possible to your tank.

I will use my setup as an example of this concept. I run an AE ACR in saturation mode, pressurized to 5 psi. The pH inside my reactor is high to mid 5's.

My effulent flows out of the ACR to a powered second stage, a Geo 618 with no CO2 hooked up. Then it flows through a 2" inline cannister filled with ReMag. It finishes off the journey to the sump, passing through an aeration tower that has room air bubbled through it for 90 seconds every 15 minutes.

The pH inside the Geo is 6.10 (+/- 0.03). When it exits the aeration tower it is 6.8 - 7.2 (depending on time of day, higher at night).

My effulent tests at a steady 90 dKH. My baseline flow rate is 8 ml/min. I slow my reactor at night and boost it during peak light hours.

My tank pH over the past 24 hours (tested every 6 hours) was 8.31, 8.27, 8.37, 8.42.

I was dosing kalk, but took it offline to make my tank more tank sitter friendly (it needed to be mixed every 4 days).

I have a lot of systems in place to combat low pH. All the CaRx ones already mentioned, plus outside air to my skimmer, a skimmer pump inside my fuge barrel, an HRV system, etc.

With all that being said, my belief is that to limit the potential pH drop you can get from a CaRx is to limit the amount of effulent required to as little as possible by making it as potent as possible.

When BRS did their video testing if a secondary chamber raises pH, they found that it did not raise the pH to any degree, but greatly strengthened the effulent. So they concluded no, it doesn't raise the pH.

I think they missed the forest for the trees, because having effulent that is 50% stronger (what their test showed), would allow you to dose much less effulent, and get much less drag on your pH as a result. So even in their test, a higher tank pH would result, though they failed to point that out.

So long story short, flow your effulent over as much media as possible, preferably in a powered active stage, to get every last bit of dKh out of the CO2 used. That should give you the highest tank pH while using a CaRx.

Have you wondered with this approach of strongest effluent possible at what point you’re going to start precipitating CaCO3 back out as the pH comes back up?

Maybe an equally sound approach would be to keep doing what you’re doing but take steps to prevent precipitation before it reaches a high flow area of your sump. I guess once the solution is in your water column and with dKH so high you won’t see much of a pH drop anyway

 

[Dennis Cartier]

Have you wondered with this approach of strongest effluent possible at what point you’re going to start precipitating CaCO3 back out as the pH comes back up?

Maybe an equally sound approach would be to keep doing what you’re doing but take steps to prevent precipitation before it reaches a high flow area of your sump. I guess once the solution is in your water column and with dKH so high you won’t see much of a pH drop anyway

I already have precipitation at different points in the process.

Before I built the aeration tower, I ran a test where I dripped my effluent into a ABS pipe with an air stone in my sump. I was really looking to see if I could detect a rise in the tank pH to confirm that the excess CO2 could be blown off. What I got instead was a drop in alk and lots of calcite flakes. So I knew that the idea was viable, but would need to be controlled.

Initially I used a pH probe in the aeration tower's water column, along with a pH controller to turn the air pump on until a desired pH was reached. That worked for awhile, but the clear PVC of the aeration tower started to fog with precipitation. Eventually the precipitation also affected the pH probe, decreasing it's response. So I abandoned the idea of cycling the air pump based on pH and instead used a periodic timer. Not as precise, but also immune to precipitation.

I don't mind a bit of precipitation in exchange for a stable effluent dKH. My dosing regiment needs to know the volume of effluent dosed, and at what strength (dKH). So it's a good trade off.

 

[Saltyanimals]

This is something that I have been pondering lately. How to get the least amount of pH drop while using a CaRx. Which correlates nicely to your situation.

What I believe is that you need to shoot for the strongest effulent possible, so you can dose as little as possible to your tank.

I will use my setup as an example of this concept. I run an AE ACR in saturation mode, pressurized to 5 psi. The pH inside my reactor is high to mid 5's.

My effulent flows out of the ACR to a powered second stage, a Geo 618 with no CO2 hooked up. Then it flows through a 2" inline cannister filled with ReMag. It finishes off the journey to the sump, passing through an aeration tower that has room air bubbled through it for 90 seconds every 15 minutes.

The pH inside the Geo is 6.10 (+/- 0.03). When it exits the aeration tower it is 6.8 - 7.2 (depending on time of day, higher at night).

My effulent tests at a steady 90 dKH. My baseline flow rate is 8 ml/min. I slow my reactor at night and boost it during peak light hours.

My tank pH over the past 24 hours (tested every 6 hours) was 8.31, 8.27, 8.37, 8.42.

I was dosing kalk, but took it offline to make my tank more tank sitter friendly (it needed to be mixed every 4 days).

I have a lot of systems in place to combat low pH. All the CaRx ones already mentioned, plus outside air to my skimmer, a skimmer pump inside my fuge barrel, an HRV system, etc.

With all that being said, my belief is that to limit the potential pH drop you can get from a CaRx is to limit the amount of effulent required to as little as possible by making it as potent as possible.

When BRS did their video testing if a secondary chamber raises pH, they found that it did not raise the pH to any degree, but greatly strengthened the effulent. So they concluded no, it doesn't raise the pH.

I think they missed the forest for the trees, because having effulent that is 50% stronger (what their test showed), would allow you to dose much less effulent, and get much less drag on your pH as a result. So even in their test, a higher tank pH would result, though they failed to point that out.

So long story short, flow your effulent over as much media as possible, preferably in a powered active stage, to get every last bit of dKh out of the CO2 used. That should give you the highest tank pH while using a CaRx.

Hey @Dennis Cartier mentioned his strategy is to run the strongest effluent possible in minimize the low pH effluent volume entering the tank. This makes sense to me logically and as he has take the time to experiment in his own system. However this seems to contradict what @Sisterlimonpot said earlier about raising the effluent volume. So which one is it? =)

I'm going down different pH rabbit holes right now and research to see where I can minimize the CaRX as a big Co2 contributor to the tank so I have less pH uphill battle.

I'm using Reborn (original size 2023) and not course. Package says pH 6.7 yet I'm seeing melting point of 7 mentioned in this thread. That 7 would be awesome and will target that point as well to see if I can still get it to melt in my tank. Assuming at that 7 pH for the reborn, I will get it as close to 10-15 ml/min, but I just don't see myself getting any where under that effluent volume.

 

[Dennis Cartier]

Hey @Dennis Cartier mentioned his strategy is to run the strongest effluent possible in minimize the low pH effluent volume entering the tank. This makes sense to me logically and as he has take the time to experiment in his own system. However this seems to contradict what @Sisterlimonpot said earlier about raising the effluent volume. So which one is it? =)

I'm going down different pH rabbit holes right now and research to see where I can minimize the CaRX as a big Co2 contributor to the tank so I have less pH uphill battle.

I'm using Reborn (original size 2023) and not course. Package says pH 6.7 yet I'm seeing melting point of 7 mentioned in this thread. That 7 would be awesome and will target that point as well to see if I can still get it to melt in my tank. Assuming at that 7 pH for the reborn, I will get it as close to 10-15 ml/min, but I just don't see myself getting any where under that effluent volume.

I stand by my original position, strong effluent allows you to dose much less of it, and should affect pH less. In my opinion, the key is using up as much residual CO2 in the effluent as possible, converting it to supplementation.

I am running a thread in the experiment section involving similar concepts, though not trying to test the relationship between effluent strength and pH, instead the relationship between effluent strength and CO2 saturation. I am still waiting on some 3D printed parts, so the experiment has not yet launched.

Super Saturated Small Media Bed Reactor Theory

This thread is to study the effects of operating a super saturated small media bed CaRx (S3MBR) using the super saturation of CO2. The premise is that a S3MBR should be able to to achieve performance equal to, or exceed the performance of traditional larger CaRx reactors that rely on media...

www.reef2reef.com

 

[Saltyanimals]

I stand by my original position, strong effluent allows you to dose much less of it, and should affect pH less. In my opinion, the key is using up as much residual CO2 in the effluent as possible, converting it to supplementation.

I am running a thread in the experiment section involving similar concepts, though not trying to test the relationship between effluent strength and pH, instead the relationship between effluent strength and CO2 saturation. I am still waiting on some 3D printed parts, so the experiment has not yet launched.

Super Saturated Small Media Bed Reactor Theory

This thread is to study the effects of operating a super saturated small media bed CaRx (S3MBR) using the super saturation of CO2. The premise is that a S3MBR should be able to to achieve performance equal to, or exceed the performance of traditional larger CaRx reactors that rely on media...

www.reef2reef.com

does strong effluent = low pH effluent too?

My CaRX pH shows high 6.8x and assuming that’s enough to melt a particular media type, I would imagine the effluent as it immediately exits the tube is about the same as the pH in the reactor. So wouldn’t it make sense to keep the exiting effluent as high a pH as possible so it doesn’t drag down the tank pH?
I’ll definitely take a read of your experiment. Will be interesting to try and burning off as much Co2 as possible from there. I’m trying to get the tank pH as high as possible before a final boost of NaOH which is another experiment I’ve been doing for several weeks now.

 

[YOYOYOReefer]

i would add a second chamber , my reactor holds about 80-90 lbs of media. is 2 32 inch tall 8 inch diamter tubes and the extra container is 6 inch diameter 24 inches tall.. system is 2 300 gallon displays plus a sump. i dont get any massive ph movements if its turned on or off.

 

[Dennis Cartier]

does strong effluent = low pH effluent too?

My CaRX pH shows high 6.8x and assuming that’s enough to melt a particular media type, I would imagine the effluent as it immediately exits the tube is about the same as the pH in the reactor. So wouldn’t it make sense to keep the exiting effluent as high a pH as possible so it doesn’t drag down the tank pH?
I’ll definitely take a read of your experiment. Will be interesting to try and burning off as much Co2 as possible from there. I’m trying to get the tank pH as high as possible before a final boost of NaOH which is another experiment I’ve been doing for several weeks now.

does strong effluent = low pH effluent too?

It can, but it does not have to. Any excess CO2 in the effluent that has not been used to increase the effluent strength is going to drag down the tank pH. A good example of this is the BRS video I mentioned earlier. They were attempting to validate the claim that a secondary chamber raises the effluent pH. What they found in their test was that the pH increased by 0.05 pH, so not very much, but the effluent strength increased by 50%. So the secondary chamber was using up excess CO2 and creating stronger effluent.

 

[Saltyanimals]

does strong effluent = low pH effluent too?

It can, but it does not have to. Any excess CO2 in the effluent that has not been used to increase the effluent strength is going to drag down the tank pH. A good example of this is the BRS video I mentioned earlier. They were attempting to validate the claim that a secondary chamber raises the effluent pH. What they found in their test was that the pH increased by 0.05 pH, so not very much, but the effluent strength increased by 50%. So the secondary chamber was using up excess CO2 and creating stronger effluent.

Ahhh yes. I remember that video. I'll have to watch again, but I recall the 2 points you reminded: 1) 2nd chamber didn't have the return on investment effort from a pH perspective but 2) they did pass it through more media creating that stronger effluent.

I'm now on year 2 of my CaRX and have never tested the effluent. It was "tuned" in my opinion because it was providing a steady Alk. Now on the pH journey, it may not be as tuned as I thought b/c it was negatively impacting the pH for the tank. I finally tested the effluent * and it reads 10.2 dkH. CaRX pH is 6.8x That's much less than the 25 dKh starting point in various tuning docs I read. That tells me I need to double the strength and in doing so will also create a lower pH solution.

Following @Dennis Cartier lead, I will further reduce the 20ml/min down to 10ml/min will increase contact time, bring down CaRX pH and effectively make a stronger effluent.


* Can someone help confirm that I tested this correctly with Hanna. 1) Took 5ml of effluent + 5 ml rodi. 2) added the regular reagent amount if 3) Hanna gave me a 5.1dkh. 4) I double that 5.1 so my effluent dkH is 10.2.