Calcium reactor

[lost66]

I think my Aquamaxx T-1 calcium reactor became too small for my tank. I have difficulties finding a new reactor because "up to XXX gallons" is deceptive. Aquamaxx T3 is up to 1000 gallons but other brands with similar size say like up to 400 gallons. I don't know how "well stocked" is my tank and if I really have to upgrade my reactor.

This is what I have:
reactor flow rate https://photos.app.goo.gl/qPjMEvM4apDNVeFu8
reactor bubble counter https://photos.app.goo.gl/FTGcbEw8jBeBc2767
and my tank overview https://photos.app.goo.gl/pGtvC3vVHBo52GrG9
Having this setup my alk is decreasing 0.1 a day.

Any advises?

 

[KrisReef]

I think my Aquamaxx T-1 calcium reactor became too small for my tank. I have difficulties finding a new reactor because "up to XXX gallons" is deceptive. Aquamaxx T3 is up to 1000 gallons but other brands with similar size say like up to 400 gallons. I don't know how "well stocked" is my tank and if I really have to upgrade my reactor.

This is what I have:
reactor flow rate https://photos.app.goo.gl/qPjMEvM4apDNVeFu8
reactor bubble counter https://photos.app.goo.gl/FTGcbEw8jBeBc2767
and my tank overview https://photos.app.goo.gl/pGtvC3vVHBo52GrG9
Having this setup my alk is decreasing 0.1 a day.

Any advises?

What is the dkh of the outflow?, Or is it saturated? (I don't remember the number, I think saturation is something like 20 dKh?

Otherwise, I would be suspecious of the cat. I had my wife watch the video and the tank is beautiful but we both loved the kitty!

Bump!

 

[HuduVudu]

I think my Aquamaxx T-1 calcium reactor became too small for my tank. I have difficulties finding a new reactor because "up to XXX gallons" is deceptive. Aquamaxx T3 is up to 1000 gallons but other brands with similar size say like up to 400 gallons. I don't know how "well stocked" is my tank and if I really have to upgrade my reactor.

This is what I have:
reactor flow rate https://photos.app.goo.gl/qPjMEvM4apDNVeFu8
reactor bubble counter https://photos.app.goo.gl/FTGcbEw8jBeBc2767
and my tank overview https://photos.app.goo.gl/pGtvC3vVHBo52GrG9
Having this setup my alk is decreasing 0.1 a day.

Any advises?

Wow this is a far cry from where you were before trying to get before a low flow through the reactor. I am with @KrisReef it seems like you don't have you tank dialed in. I get 25dKH for my effluent and I am running very very low bubble count (1 per 20 minutes) and 450ml per day. My tank, TBF is low demand relatively speaking but what you are dealing with seems really excessive.

@jda has a document out there on properly setting up reactors. but I don't have the link because I downloaded it. Here it is though in text. Maybe this can help you.

Some copied and pasted stuff from over the years. I will try and keep this document green and updated from time to time. If anybody has any suggestions, send me a PM on RC or r2r - jda on both. Feel free to send this link to anybody who might need it.

Preface:
This is for people who want to learn how to use and tune a CaRx. If you want to let a controller do it, then you will probably be disappointed in this content.

Reactors in General:
Most reactors are all pretty similar - they recirculate water, let in tank water, let in co2 and let out effluent. They are simple beasts. Built quality matters. That being said, there are literally a dozen brands that are totally fine - I use Korallin, but I would also use GEO, LifeReef, AquaMaxx, Knopp and many others. I like reverse flow, but with larger media not clogging as much, it is not as big of a deal as it used to be.

You can spend a fortune on regulators and stuff, but if I were starting over, I would just buy a Tunze and call it a day. I have a very expensive dual stage stainless Victor with oil filled gauges and a custom needle valve - the dude that I got it from spent like $750 on it and while it is nice, it does not do any better of a job than the Tunze that I am using, or a m3 regulator. The expensive ones are easier to fine tune, but you can fine tune a cheaper one just as well. You can always add a super-precision needle valve to a "normal" regulator.

A good check valve is super important to keep saltwater out of your nice regulator if power goes out.

I would skip the ph probes and learn how to tune this thing by hand - it is easy, more reliable and will save you trouble down the road. Take the time and learn... it seems like a lot at first, but with just a bit of effort, you will "get it" all of a sudden. Once you learn, if you want to monitor with a pH probe, then cool, but you will be better at this if you know how to do it yourself.

The only media that you can get right now is calcite or dolomite (in 2020) - if you have a LFS that has some Reborn or Natural ARM (old stock), then grab it, but it is hard to come by. The current incarnation of ARM is crushed calcite - get the medium size. The natural media has more trace elements in it than calcite, dolomite or the man-made media, so I like to use it when I can find it - the stuff is melting exactly what the coral uptook when it grew it’s skeleton. Nov 2020 edit: ARM calcite appears to have a good amount of traces in it as well… it is keeping up with magnesium and strontium (had to dust off the test kits). Reborn is available from time to time also, but not consistent.

I feed with a cheap pump like a Quietone 1200 or Maxijet - they seem to last 3-4 years, but they are like $20 to replace so no big deal. I also use a mainline T on one system. You can get an expensive dosing pump (Kaomer, for example), but make sure it is continuous duty. Some reactors will feed themselves, so check this out first. They all work plenty well. DO NOT run a calcium reactor off of a manifold.

If you tune your reactor well, a second chamber will do nothing. If you plan on learning how to tune, then no need in buying one, but if you are sure that you want to use a pH monitor and probes, then get one for sure.

If it were me, I would try and find a used high quality reactor - Geo, Korallin, etc. Buy a new Tunze Regulator. Get a Mainline T to feed. Get a flow control pinch to control the output. Find a 20lb bottle locally - 5 or 10lb are fine, just need refilled more. Get some co2 safe tubing. Order some ARM. Get a Salifert Alk test kit - cheapest and easiest to check effluent. You should be able to do all of this for a few hundred bucks... or you could max out, and go over, that whole stimulus check if you really wanted to.


How to tune:
Set your reactor to 40 drips and 10 bubbles per minute. Wait 24 hours and test the effluent dKh - the goal is around 25 dKh. If you are lower, then add a bubble, if higher, then subtract a bubble. You NEVER want to move both the drips AND bubbles at the same time when tuning. If bubbles are too hard to dial in, then you can move the effluent too… less drips if you need higher dKh and more drips if you need lower. A few bubbles or drips can go a long way. Be sure and wait at least overnight before retesting.

Once you are around 25 dKh, see if it will stay there for a few days. If it does, then measure your effluent rate in MLs as well as drips (eventually, you will not be able to count drops anymore). This number of bubbles and drips is your magic ratio.

Now that you know your magic ratio, then you move BOTH drips and bubbles in this same ratio to meet tank demand - up or down together.

Notice that I did not say anything about pH or a controller or probe. I do not use them and do not recommend that anybody does. They are a waste of my time and provide substandard results over tuning for 24x7 operation.

Hang in there. It might seem hard at first, but usually people get it quickly and it all makes sense. Typically people send me PMs for help and then they stop about mid-way because they start to understand. It will get to the point where you will be able to just look at the effluent rate and bubbles and have a pretty good idea of where you stand.

Few tips:
Somewhere around 25 dKh for effluent output is fine… do not fret over the exact number.
If when you raise or lower in your magic ratio, the dkH moves to 22 or 28, then who cares… if it is keeping up with the tank demand, then leave it alone.
Over time, as your tank demand increases, you will need to increase the output of your CaRx - make a slight increase and test the tank and you should see it slowly rise and then level off. I have to increase mine every few months and it might go something like this… Jan 1 tank dKh of 7.3 which slowly lowers to 6.8 on April 15th and then I turn the CaRx up just a bit which raises the tank dKh up to about 7.2 over the next few weeks, then levels off and then drops again to 6.8 some time in September. The CaRx does not keep the tank completely stable since my demand keeps going up and up as corals/clams/coralline grow, but just small adjustments are all that is necessary to keep up.
Test and pay attention to dKh at the same time every day. Do not worry if your night vs day dKh moves a bit… this is normal.


About pH in the chamber:
It is worthless when dealing with output. The media type, surface area and density will all matter, so the pH needed in one system is different than the media in another. This is the same with bubbles and drips. Take into account that there is no uniform media, bubble or drop sizes and you can see why people just cannot tell you X mls per minute, Y CFM of co2 and Z pounds of media. Your experience with one type of media to the other will require a small tune.

About co2 tanks and gauges:
For low side pressure, you need to turn the knob so that the low side pressure is enough for steady bubble output. Hard to say what a good PSI is since these are not super precision regulators and they can vary by 100%, but raise it by 1 PSI if you cannot get a consistent bubble rate.

Some regulators do not have the ability to adjust the low side PSI - this is fine, one less thing to worry about.

The gauge will show about 800 PSI until the last droplet of liquid co2 is still liquid. The high side gauge will only go down once the tank has nothing but gas in it - this means that you are empty. THIS IS NOT LIKE A GAS GAUGE so remember your simple high school education about expanding gasses in liquid state. You can pick the tank up and see how full or empty it is. Some keep the tank on a mechanical scale and use the scale measurement as a “gas gauge.”

I like to use 20lb tanks, but I have a basement sump and the room is no problem. I have 3 systems using CaRx and I do keep a spare 5lb tank in the garage that is full in case I run out. You can get cheap 5lb tanks from failed home brewers and the like.

Home brewing and/or welding supply shops can fill your tanks with co2.

Salifert Test Kit for High dKh:
(this is from a test kit that I purchased in 2019 - they change all the time, so read the directions)

Follow the directions for the low-res mode - 2mls of tank water and 1 drop of the blue stuff, I think. If you use all 1ml of the final syringe, then get another ML and add the results together.

So if you use 1 syringe and .28 of the next one, then it is 32 for the first syringe (low res) and 9.6 for the part of the second one... for a total of 41.6.

The low res mode goes to 32, so that should cover most CaRx. Also, put the remaining final solution back into the bottle - it goes further this way since I never run out of drops before the larger bottle.

You can use normal resolution mode too, just will nearly always require more than one syringe of the final liquid.

Using pH Probe and Controller:
I do not recommend this until at least you learn how to tune a reactor on your own. You cannot trust the pH probe forever, so you have to know when you need to intervene. I have not used a pH controller for at least a decade and do not have any advice on what to buy or how to use them.

This is the same with the fully automated CaRx setups. The best thing to do with these is to just go 100% into what the manufacturer is saying ang selling.

If you want to use a pH meter to alert you if something is WAY out of whack, then cool, but only have it alert and not stop/change anything. The pH probe is BY FAR the least reliable piece of equipment here, so test by hand before you ever trust what it told you. Some people have them alert if the chamber pH gets above 7.0 which might mean that the tank is empty.

My Favorite Combo:
I should note that I would use nearly any good and well built CaRx and that the differences are very minor. Use setups are a good way to save money. I am only writing this because people ask me quite often.

If I were buying today (new), I would buy a Korallin Reactor, Tunze Regulator, get a 20lb bottle locally, use a MaxiJet 1200 feed pump and find medium sized media (natural if possible).

I like the Korallin because the Ehiem pumps usually last more than a decade and are efficient, reverse flow (can be used with really small media like crushed coral), like that the pump is on top to keep the debris from clogging the effluent line (most debris settles on the bottom) and have a small footprint. I also like that they have survived a few economic downturns and are still in business in case I need parts (2007-2009 was a killer). The Korallin also traps excess co2 at the top and I can tell if my tune needs adjustment.

I have used Geo, Tunze, Korallin, Knop, AquaMaxx, LifeReef, RO and many other reactors and they are all fine. Currently using a Tunze, M2 and Home Made regulator and they all are steady and reliable. I do not use the Aquarium Plants Carbondoser anymore since they seem to only last a few years for me - they are amazing when working. There truly are many, many quality pieces of equipment out there for doing this.

I won an AquaMaxx at a club auction and this unit has a prefilter that traps/captures all small particles and organics and keeps them from entering the reactor. All reactors should add one of these immediately. I love this feature even though I hate other things about this reactor - such is the case with all of them.

Threads to Browse:

calcium reactor cant keep up with alk

I have a korallin calcium reactor that is working great but it cant keep up with my demand. I have the effluent all the way open and ph set at 6.4 inside. Would adding a second chamber help a lot or not really? I really do not want to buy another whole calcium reactor right now. If a second...

www.reef2reef.com

Calcium Reactor Dial-in Assistance

hi everyone. I have a Geo CR618 reactor that has been running for about 4 weeks now. 3 with CO2 added. I have been bumping the reactor down very slowly due to this being my first reactor and I didn’t want to do too much at once. The reactor is still not quite meeting the ALK demand of the tank...

www.reef2reef.com

Dialing in a new CaRx- How long to wait after adjusting Effluent pH or Flow?

I've heard a little as 3 hrs and as much as 48 hrs. I haven't played with one before so I figured I'd seek advice. Let me give a simple scenario: (Transitioning over from Triton Core7 BTW) I calculate my effluent dKH and it's 15 dKH. Flow is at 30mL/Min. I test the tank...opps... the levels...

www.reef2reef.com

 

[lost66]

What is the dkh of the outflow

9.0

Maybe this can help you

Thanks, it was enlightening.

I see there are 2 schools of running calcium reactor. One with constant bubble flow and second one with ph based. I am confused, all sources tell me to use ph probe, all valves for reactor are selenoid based.

At this point I think what I am doing wrong. When I noticed alk going down I raised the flow. When that wasn't catching up then I added more bubbles. And finally I think co2 doesn't have enough time to dissolve media.

Does the size of reactor matter? Or is it only how often do I have to refill chambers? Or maybe the bigger reactor allows to accumulate more liquid with higher alk so I can have more drops in the outlet?

 

[HuduVudu]

One with constant bubble flow and second one with ph based. I am confused, all sources tell me to use ph probe, all valves for reactor are selenoid based.

People use the PH probe because they are trying to get the controller to manage the reactor. I REALLY don't suggest doing this. Lots of years in automation have shown me that using sensors in feedback is really not stable or safe especially when that sensor is a PH probe. That is why JDA suggests not using probes. I concur with this.

So the "right" way is to set the bubble count and flow and then adjust according to the ratio as the corals start to grow. Doing it this way is incredibly stable. In the article he suggests getting the output dKH to 25. This will be a baseline. It basicly ensures that you are indeed melting CaCO3 and that you are in the ball park for where you need to be. When you get the output up to area of this number. Then note the ratio of bubbles to effluent output. This gives you a ratio. The measurment types (e.g. ml/minute or bubbles/sec) don't matter other than when you calculate you need to keep the same types of measurements. So for my tank. I have one bubble for every 20 minutes and 450ml/day of effulent output. One day is 1440 minutes and this will be ~0.3 ml per minute so 6.25 mll for 20 minutes. Now I can get my ratio ... 1 bubble per 6.25ml. When you have that you can now make adjustments up and down. If I change my bubble count I will have to keep the ratio that I have just calculated. So if I want to change my output and double it, I will then need to adjust the effluent to 2 bubbles per 12.5 ml (2x 1 bubble/6.25ml). This doubles the amount out of the CaRx while keeping the effluent dKH at 25. So for my example I will dial in 1 bubble per 10min (2 bubbles per 20min) and 0.6ml/minute (12.5ml / 20minutes or 0.625ml/minute) on the doser.

To note I do use a seloniod, but it it "dumb" and the reason I do it is to get my bubble count to the very low number that I am using. I do not use a PH probe for feedback.

Does the size of reactor matter? Or is it only how often do I have to refill chambers? Or maybe the bigger reactor allows to accumulate more liquid with higher alk so I can have more drops in the outlet?

The size of the reactor is really not a consideration for almost all home hobbyists. The only thing the chamber really does is determine how often that you need to add new media. Think of it like a top off container. The bigger that it is the less that you have to refill it. If you are evaping a ton of water then you will really need a big top off container, or conversly you are lazy and don't want to add top off except once a year. Reactors work the same. Of course manufacturers want you to put more in their pockets so they aren't really going to talk about this but it is the truth. For me ease of changing the media would be better than a larger reactor.

Sooooo ....
At 9 dKH it is very unlikely that you melting anything i.e. your reactor is not doing anything except being a very large paper weight. With this said if your tank is low demand when you start to dial in the reactor the alk in the tank is giong to jump very high very quickly this is what I have been dealing with. That jump isn't good, just note that it is even worse if you try to jack it back down. This process will be very stressful on your corals. So start with very very low input numbers. Where mine are at would be a good start for you.

I am glad I caught your post because I wanted to write to you again, about dosing pumps. I was using the Kamoer FX-STP for my CaRx. I was worried that regular dosers wouldn't be able to push through the CaRx. The problem is that the FX won't go very low for output (0.1/ml per minute) because it is continous duty. I just switched over and tested the Kamoer X1 bluetooth through the CaRx. It has plenty of horsepower to get through, and it has the added benefit of allowing me to set the effluent rate much lower. Just wanted to share that with you.

Ok, this was rather long, but I hope that it helps clear some things up.

 

[biecacka]

@HuduVudu duyu (see what I tried to do there?) How do you like that pump, I am looking for a pump for my CaRx and was considering that one.

corey

 

[HuduVudu]

@HuduVudu duyu (see what I tried to do there?) How do you like that pump, I am looking for a pump for my CaRx and was considering that one.

corey

I am watching u and the hudu vudu you dun did du ;Pompus

I like the pump it is very basic. Twelve settings per day. It is blue tooth and you need to be close to connect. I am not particularly cost conscious, but the price is nice. One of mine came in with a bunk head, I bought two. I cleaned it up and re-aligned and re-lubricated, after two times of this it is now working solidly. The output is surprisingly strong. Would definitely buy again. Especially considering that bluetooth offers a lot of privacy.

I just switched over the pump to the CaRx two days ago. Not a lot of info, other than it works. I have a Korallin reactor. I calibrated the pump running through the reactor, and if I remember correctly it was 20ml/min this might be a low for a higher demand tank, but works particularly well for my situation.

Hope this helps.

 

[biecacka]

I am pretty familiar with how JDA runs his CaRx and I ran a version of that before I moved. But I fed the reactor off the return pump manifold. So it was more difficult to adjust the flow and not have it clog the effluent. No manifold on the new setup so I’m debating a pump like that or just a maxi jet or the likes.

corey

 

[KrisReef]

I am pretty familiar with how JDA runs his CaRx and I ran a version of that before I moved. But I fed the reactor off the return pump manifold. So it was more difficult to adjust the flow and not have it clog the effluent. No manifold on the new setup so I’m debating a pump like that or just a maxi jet or the likes.

corey

I put a dosing pump on my system because I got tired of having to constantly adjust the flow as the manifold pressure moved about. Steady flow and stable bubbles are required, ime.

 

[biecacka]

That is why I didn’t put a manifold on the tank this time. But I am not opposed to just using a small power head to feed the reactor as well.

corey

 

[HuduVudu]

That is why I didn’t put a manifold on the tank this time. But I am not opposed to just using a small power head to feed the reactor as well.

corey

I don't really have a sump so for me a power head is not an option. If I did have a sump I also wouldn't use because the flow would be too high and I the adjustment is difficult. It is easy to just remake the plan and adjust the flow on the dosing pump.

 

[biecacka]

I agree 100% that is why I am considering a dosing pump.


corey

 

[lost66]

Wow this is a far cry from where you were before trying to get before a low flow through the reactor. I am with @KrisReef it seems like you don't have you tank dialed in. I get 25dKH for my effluent and I am running very very low bubble count (1 per 20 minutes) and 450ml per day. My tank, TBF is low demand relatively speaking but what you are dealing with seems really excessive.

@jda has a document out there on properly setting up reactors. but I don't have the link because I downloaded it. Here it is though in text. Maybe this can help you.

Thanks!
My alk dropped to 6.9 yesterday so I have to slowly raised it and then I will tune as you/person from that article suggested. I have been running my reactor for a year and I was surprised how slowly media melts. Maybe 20% per a year... Now I know why.

My reactor came without this blue round plastic thing at the bottom. Reactor has a mud at the bottom. Is this part required or only a helper to aligned tube when assembling?

I pulled the trigger and purchased kamoer X1 PRO T Stepper Pump and I am in the process of returning it because it was too laud. I contacted their support and said it is normal sound, I was running it too fast. Totally BS and BRS was so great they allowed me to return it after after days of purchase. They just bought me for good
I was able to purchase FX-STP from my local reefer for $50 and so far I am loving this pump. @HuduVudu I hope I will be able to use it.
My reactor feeds from main return line - what is wrong with such approach? There is no need to have a high flow into reactor anyway.

My main concern at this point is to start tuning because when I change bubble/flow rate my tank will not get the proper amount of alk for some time. I think I will just test twice a day and dose alk manually until I have stable ~25 alk from the reactor.

 

[HuduVudu]

My reactor came without this blue round plastic thing at the bottom. Reactor has a mud at the bottom. Is this part required or only a helper to aligned tube when assembling?

Oopps you need that.

The water is being pushed from under this blue plate into the media. This plate spreads out the flow and keeps the water from channeling through the media. If you are confused by the word channeling do some research. It is an important idea to understand. I think you will be fine for now, but I am not sure for how long. I guess it is best to work with what is set up for now, but definitely when you change the media put that piece back in.

I was able to purchase FX-STP from my local reefer for $50 and so far I am loving this pump. @HuduVudu I hope I will be able to use it.

I still use mine I just switched it to a place that it will work better ... top off.

My reactor feeds from main return line - what is wrong with such approach? There is no need to have a high flow into reactor anyway.

You don't want to feed from the main line because the pressure on the line changes (pretty significantly). This will cause you to have an inconsistent flow ... even through a dosing pump. You are going to want to move that off of your mainline and take your input directly from your sump or your tank.

My main concern at this point is to start tuning because when I change bubble/flow rate my tank will not get the proper amount of alk for some time. I think I will just test twice a day and dose alk manually until I have stable ~25 alk from the reactor.

You will be surprised at how quickly the reactor will come online, and when it does you will be getting more alk and calcium than you know what to do with. You can get it tuned and working within an hour. It will stabilize with two or so hours. I wouldn't start dosing I would use the reactor to bring it up. You will be able to do that quickly when you get it tuned. I am going to go ahead speculate that you will get too much alk when you check tomorrow. I had to run my FX-STP at 0.3ml/min so you can maybe start there. I don't know how you are dealing with your bubble count. If you are doing it by hand (you don't have a soleniod) try for something like 1 bubble per second. Then adjust your dosing pump to get you where you need to be. I found it too frustrating not having precise control on the bubble count, so if you don't have one you might consider a soleniod.

 

[lost66]

What is the difference between "mainline T" and manifold?

 

[HuduVudu]

What is the difference between "mainline T" and manifold?

A tee is a one output manifold.

Yes, I am butchering the word but that is essentially what it is.

Either way you are branching off of some sort of return pump. Doing this provides a very inconsitent output because of the pressure changes (head) from the output pump.

 

[lost66]

I think I am missing something here. What is the difference between external feeding pump and my main return pump? Both are the same technology so why main pump loses pressure? Both are in the same place, I think all variables are static.
also, when reactor's output is few drops once a while and input comes with a much more flow then even if the pressure is changed a little bit for even like a minute then how does it affect reactor?
I am trying to avoid another device in my stand if possible.

 

[jmichaelh7]

Look up on this forum about calcium reactors. It seems you have a lot of questions that can benefit from the advice a couple of these experienced reefers share. I was in your boat only 2 weeks ago … my tank is dialed in now

 

[lost66]

Initially I had ~25dkh in the reactor but I think I cranked the flow too much and I lost it. It was around 16dkh. I reset it and trying again but with raised values. 20 bubbles and 60 drops. I opened the valve more so the low pressure needle moved a little hoping I will be able to have stable bubble count. I tuned it last night so tonight I will measure alk in the reactor.

I elevate alk level by dosing. In few days I should be on ~8 so I can start to increase the output. BRS has a very nice video showing the process with that nice calculator.

What I don't really understand is why I don't need to use ph probe to control reactor. Right now I have 5.9ph inside, all sources say ph around 6.5-6.7 melts media in the optimal speed.
I have missing that blue plate on the bottom of the reactor, maybe this affects. I have some scrap acrylic, I think I will try to retrofit that part. I can imagine how it may affect the process as @HuduVudu suggested.

 

[FishTruck]

I think I am missing something here. What is the difference between external feeding pump and my main return pump? Both are the same technology so why main pump loses pressure? Both are in the same place, I think all variables are static.
also, when reactor's output is few drops once a while and input comes with a much more flow then even if the pressure is changed a little bit for even like a minute then how does it affect reactor?
I am trying to avoid another device in my stand if possible.

If you are feeding with a manifold, then, every time you fiddle with valves the feeding pressure to your reactor will change. This is a disaster f you are trying to use pH to control your reactor with a solenoid shutting on and off (not recommended), your ALK delivery will be all over the place. The other danger is how much pressure might be in the system from your main pump. A big pump can crack your reactor.

On the other hand, if you can just maintain a stable bubble rate (one that does not react to small changes in effluent rate), then small changes in the effluent don't really affect the alk delivery that much, even though the pH in the reactor can go up and down a bit.