Review of Joe_P's calcium reactor

[robe]

The ph controller should be in the tank instead of the reactor. The controller is to prevent the tank ph from going too low.

I have never used a controller in my reactor. I just drip 24x7 and the tank ph is around 7.9 in the morning and around 8.3 -8.4 by the time the lights go off at night.

There are a lot of reefers in RC who does not use controllers as well. In a well aerated tank the ph dip should not be a problem. The effluent should be dropped to a high flow turbulent section to enable the excess CO2 to dissipate.

The best point of introduction should be in the output of the overflow pipe .

[Joe_P]

But why do you need the IKS to control the pH inside your CR? Do you mean you tune the IKS to switch the CO2 supply off when the pH drops to your preset level?

If I have the $$$... would definitely consider a pH probe inserted into my CR....

a pH probe would defnitely help alot in keeping the pH of the solution in the reactor consistent... only releasing CO2 when pH increases and cutting off supply when the set pH value is met....

You would then not be required to always tune your reactor's CO2 supply... jus reply on the probe and pay attention to the effluent drip to obtain desire CA/alk levels....

my 2 cents...

[Michael Young]

If I have the $$$... would definitely consider a pH probe inserted into my CR....

a pH probe would defnitely help alot in keeping the pH of the solution in the reactor consistent... only releasing CO2 when pH increases and cutting off supply when the set pH value is met....

You would then not be required to always tune your reactor's CO2 supply... jus reply on the probe and pay attention to the effluent drip to obtain desire CA/alk levels....

my 2 cents...

Joe, I know the value of having a pH probe in the CR but I was actually puzzled why is Weisoon's reactor's pH probe connected to the IKS controller. Logically, the probe should be connected to a pH monitor not controller.

[Achilles Tang]

Mike, that's why its called a Controller!! It's not just monitors but switches off or on any equipment according to the set parameters.

[Michael Young]

Mike, that's why its called a Controller!! It's not just monitors but switches off or on any equipment according to the set parameters.

Duh AT, I know what it does. I'm using a unit myself.

I'm confused because if I understand his earlier post correctly, he's using both pH modules to control his tank and CR effluent pH.

But my question is: If one module of the controller is use to maintain the pH of the tank by turning the CO2 supply on or off, then what does the other module which is connected to the CR do? This module can't also be controlling pH because the solenoid regulator is already connected to the tank pH module. If he's using this controller module for monitoring purpose only; it would be an overkill because these IKS modules are really expensive!

Weisoon, IMO its better to let the CR run 24/7 and just regulate the CO2 according to the pH value of the tank instead.

[AlfaRomeo]

Michael, if the tank is large enough and the effluent is dripped in a very high flow area , the effect of the effluent on the tank PH would be minimal right? If that is the case, then the control should be on the PH probe in the CR. Set a target at lets say 6.8 and control the solenoid to shut off when it reaches the set value.

PH of the tank would be just monitored only to see that its in the normal range of 8.0 to 8.4 and not controlled by injection of CO2?

This is what i understand and might be wrong.. hehe

[weisoon]

Indeed the function of the PH probe in the Probe holder is to open and close the CO2 solenoid. In addition, it is also a safety device to prevent excessive CO2 entering the system in case of of valve failure. Be it fully open or half close causing the PH to drop too low range like what Alpha said. These are the main function.

As for the function of the probe in the tank, it is used like what I mentioned,

If the PH in tank is at 8.4, then I can stop the the kalkstirrer and run the normal distilled water topup through the IKS float switch. if PH is below 8.4, usually after lights off, then the kalkstirrer can start and the normal distilled water topup stops. Hope in this way, I can achieve enough evaporation for the kalkstirrer to drip when lights off and the main aim is to maintain a constant PH 8.2-8.4 24 hours IMHO.

At the end of the day, I needed this system because I am overseas quite often and I need a fail safe system with full control in case of any equipment failure. My family members knows nothing about reef keeping except just to top up the top up reservoir.

[Michael Young]

Weisoon, I'm clear about how you run the IKS now but your setup has a flaw because the tank pH should have priority over the CR's.

Controlling the effluent pH of a CR at the expense of the tank's pH in my opinion, is an overkill and may also be detrimental. Let's look at this scenario:

Due to some factors (e.g. night time, LS die off etc) the tank pH has fallen to 7.8 but CO2 still continues to be supplied to the CR because pH level stays above the preset low level.

In this scenario, the CR will still be supplying acidic or low pH water to the main tank even when the pH there is already low. And even if you have a kalk reactor turned on because of the low pH, it would be working overtime to no avail because what that is added would only be enough to counter the acidic water that's being injected by the CR. That's why I feel that its the tank pH that should be controlled, not the CR.

This is how it should be connected:

1. pH probe in tank.

2. When pH falls to low preset level (e.g. 7.9), the controller will shut down CO2 supply via solenoid regulator. If you have a kalk reactor with a dosing pump, it can also be programmed to come on at this moment.

3. When pH rises to high preset level (e.g. 8.5), CO2 will be turned on and kalk reactor shut down.

One thing that needs to be running 24/7 is the CR. The chamber of a CR is airtight and if circulation stops, the reaction chamber could turn anaerobic very quickly. Therefore, one should only stop CO2 supply to the CR and not shut it down completely. To adjust the pH of the effluent, you can do it manually using the aid of a pH monitor.

[Achilles Tang]

I think Mike is very correct with his explanations.

You shouldn't shut down the CR pump... even to save electricity.

[Joe_P]

I think Mike is very correct with his explanations.

You shouldn't shut down the CR pump... even to save electricity.

been readin though the post... can't seem to find any evidence of Weisoon mentioning the shut down of his CR's pump....

Hmmm .... Now where did that come from...???

[Michael Young]

When the tank PH is at 8.4, then CR will run and kalkstirrer stops and distill water top up runs.

Joe, I assumed what he said here to mean he's CR will only be turned on when his pH reaches 8.4.

[weisoon]

OK Mic, I will stop the CR by using the solenoid. Like before, will only run for 7-8 hrs and 4 hrs after light on. Main circulation will run for 24-7.

Since have another extra PH module, then might as well use it and then plug it into the CR as a safety device.

kalkstrirrer will run based on the PH and using a float switch and back up by a timer, just in case float switch fail.

[Michael Young]

Weisoon,

you actually do not need to put the solenoid on timer mode since its already controlled by the IKS pH module. Just let it run until the IKS tells it to stop.

You need not worry about your tank pH plummeting when you have the pH controller and an extra buffer in your kalk reactor.

[Cookiemunster]

Thanks guys for your comments...

I have previously considered the application of a higher volume rating pump for the CR in the bid of turning the reactors into fluidised units...

However after some consideration, place that idea on hold due to the following...

1) high initial investment in acquiring of pump

2) higher running cost of pump since CR recirculation pumps function 24/7..

decided to work on 2nd chambers instead to put the pH of the effluent into a more managable state....

If any reefers would be interested in a fluidised unit or would like to consider modifying current units into one... do let me know...

I'm thinking of using eheims 1260 to run larger units....

edwin,

I am wondering. Since media dissolves only at a certain ph, won't the second chamber be useless since the ph is usually above 7ph? (Only ARM media claims its media dissolves in ph 7) The rest, I believe need ph of 6 and below.

And if the output ph is below 7ph, then it would simply mean the bubble count is set wrongly....ie too fast. Because it would mean excess CO2 is dissolved.

I'm not very sure but I think the second chamber is more of preventing ph affluent below 7. Above that it will not help in anyway because even at ph 7, the media will barely dissolve or not at all depending on media used.

The ultimate idea is to prevent ph from being below 7.8 which up till now I do not think any calcium reactor is able to achieve without reducing its output performance.

So ultimately, it will still slowly pull the ph of the tank down if the drip rate is too high. Meaning, even the drip rate must be controlled to the point where your tank can handle (buffer) the lowered ph.

In fact, by placing a second chamber with a lower ph, crystallization of calcium back to the media will occur. So output should get worse and not better. But then I am theorizing. Cos it seems to make sense.

Perhaps the chemist should enlighten us.....TANZY????

[Hon]

weisoon,

IKS topup module have a setting which can program the amount of time given to topup. If the topup exceeded a certain pre-determined time, the topup will be cut. This is teh safety feature to safe guard in case level probe got jammed or in your case, pH still too low.

[weisoon]

The master speaks.

Any view on the extra PH probe on the CR function. I believe you tried previously?

Need to meet you to return the stuff. Thanks.

weisoon

[Joe_P]

I am wondering. Since media dissolves only at a certain ph, won't the second chamber be useless since the ph is usually above 7ph? (Only ARM media claims its media dissolves in ph 7) The rest, I believe need ph of 6 and below.

I have actually used coral chips before for a CR.... didn't get much in the effluent till pH is reduced to around 6.5.... and I don't think there is any media with performance worse than that of coral chips....

In fact, reefers recommend a pH of 6.5 to 6.8 as a standard pH for most CRs...

I'm not very sure but I think the second chamber is more of preventing ph affluent below 7. Above that it will not help in anyway because even at ph 7, the media will barely dissolve or not at all depending on media used

Yup, you are right with the above statement.... if ARM does not dissolve with pH above 7, then the best a 2nd chamber would do is to balance the pH at 7 before returning any effluent to the reef...

You must however also understand that the pH in a CR is almost impossible to control without a pH probe connected to a controller which would automatically shut off the CO2 feed to a CR when the set pH is obtained (discussed by Weisoon in this thread).... IMO, both controllers and probes are expensive items to acquire.... So a CR left on its own without any monitoring/controlling device would definitely be a little more difficult to tune to maintain chamber pH consistency...

That is where a 2nd chamber would come in handy ..... as a means to control the pH.... however, if the 2nd chamber does balance the pH (lets say from 6.8 to 7), wouldn't the effluent register with better readings if some dissolving takes place???

since to get a pH of 6.8 to 7, some reaction should take place ???

I'm currently testing the differential of CA/dkH readings between effluent from main chamber compared to effluent which have passed through a 2nd chamber.

Notice a increment with my previous bubble count of 1 bubble per 3-4 seconds...

I have up the bubble count to 1 bubble per second in the bid to lower the effluent pH..... with a attempt to find out whether a lower pH effluent would increase the differential between both readings......

I have been using ARM previously and did notice that the amount of CO2 pumped in does affect the readings of CA and dkH in the effluent...

Meaning if I need more, I placed more CO2 in..... seriously, my reef would be in big trouble if I keep my pH at 7 using ARM......

Which brings me to this question... and that is :

isn't the pH of a chamber related to how much the effluent registers???

[Achilles Tang]

In fact, by placing a second chamber with a lower ph, crystallization of calcium back to the media will occur. So output should get worse and not better. But then I am theorizing. Cos it seems to make sense.

Cookie,

Since the pH is low even in the 2nd chamber.... even substantially elevated calcium and alkalinity values may not have caused a dramatic calcium carbonate precipitation as you theorized.

The main causes of such CaCO3 precipitation is:

1. Ionic imbalance in the water - magnesium plays a key part. Dosing additional calcium into the tank causing supersaturation...eg. calcium chloride... and thus speeding up precipitation of calcium carbonate (and magnesium as well).

A second situation where precipitation takes place is if the supersaturation is pushed to unusually high levels. This can be caused by a rise in pH, a rise in temperature or more obviously, by a rise in either calcium or carbonate.

2. Warmer temperature found in hot spots, esp. pump impellers, pvc pipes that may have been heated externally eg. MH exposure, can cause calcium precipitation to occur there locally.

3. The uneven dissolution of CaCO3 in different parts of a reef tank.

However, because calcium carbonate precipitation can be accelerated by many key factors above as explained in detail in this article., you have to trouble-shoot accordingly.

[Cookiemunster]

I have actually used coral chips before for a CR.... didn't get much in the effluent till pH is reduced to around 6.5.... and I don't think there is any media with performance worse than that of coral chips....

In fact, reefers recommend a pH of 6.5 to 6.8 as a standard pH for most CRs...

Yup, you are right with the above statement.... if ARM does not dissolve with pH above 7, then the best a 2nd chamber would do is to balance the pH at 7 before returning any effluent to the reef...

You must however also understand that the pH in a CR is almost impossible to control without a pH probe connected to a controller which would automatically shut off the CO2 feed to a CR when the set pH is obtained (discussed by Weisoon in this thread).... IMO, both controllers and probes are expensive items to acquire.... So a CR left on its own without any monitoring/controlling device would definitely be a little more difficult to tune to maintain chamber pH consistency...

That is where a 2nd chamber would come in handy ..... as a means to control the pH.... however, if the 2nd chamber does balance the pH (lets say from 6.8 to 7), wouldn't the effluent register with better readings if some dissolving takes place???

since to get a pH of 6.8 to 7, some reaction should take place ???

I'm currently testing the differential of CA/dkH readings between effluent from main chamber compared to effluent which have passed through a 2nd chamber.

Notice a increment with my previous bubble count of 1 bubble per 3-4 seconds...

I have up the bubble count to 1 bubble per second in the bid to lower the effluent pH..... with a attempt to find out whether a lower pH effluent would increase the differential between both readings......

I have been using ARM previously and did notice that the amount of CO2 pumped in does affect the readings of CA and dkH in the effluent...

Meaning if I need more, I placed more CO2 in..... seriously, my reef would be in big trouble if I keep my pH at 7 using ARM......

Which brings me to this question... and that is :

isn't the pH of a chamber related to how much the effluent registers???

Thanks for the reply Joe,

but I don't agree on some points.

It is not hard to control the ph of the affluent without a ph probe and solenoid on the CO2. One just has to measure the ph of the affluent output. In relation to the ph, the respective calc and dkh levels can be recorded. It should come to a point where significant decrease in ph does not result in significant calc and dkh increase...thats where the CO2 has dissolved to max and cannot dissolve the media any more efficiently.

The CO2 in the media should be adjusted to where it just manages to dissolve the media and not more than that. Otherwise, it would be pulling the ph too low. In order words, too much unreacted CO2 dissolved in the water.

That is why a taller reactor body will produce higher calc and dkh levels than a shorter one. Because higher bubble rate can be used....due to bigger surface area.

I wouldn't need a second chamber if I can tune the bubble rate effectively because proper design would maximise the CO2 recirculation at a minimum CO2 usage.

However, of course, with a second chamber, it allows me to have room for more mistakes in my adjustment for bubble count, ie help to buffer ph to 7....which theoretically is the point at which the ARM media will no longer dissolve. But it still doesn't solve the problem of too low a ph to the tank.

Which can only be solved by proper reduced CO2 count. Which brings us back to square one.....proper tuning and good design of recirculation and getting a taller reactor body if higher calc and dkh is needed instead of increasing bubble count beyond a certain limit.

With regard to your question, the ph of the chamber is only one of the factors influencing the output affluent. The design of the reactor, the media used and size are the main factors.

AT:

it is precisely the points you mentioned that I am doubting the use of a second chamber. Don't misunderstand I am not saying Joe_p is making a lousy second chamber. I am just wondering if its necessary. Because I don't see a double chamber being used by even popular german brands and I think there must be some reason behind it. Cost is certainly not a concern when the prices are already so high for such brands.

And its not precipitation I am talking about. Its crystallisation. There are quite subtle differences. Precipitation occurs due to a limit in which the liquid cannot hold or reverses its solubility of another substance. Crystallization is the building of the substance onto a more concentrated structure (media) to attain a bigger crystal structure. Also known as seeding in this case.

It would be good if a few people can verify this. ie, are there any significant increase in dkh and calc levels with a second or even third chamber? What are the values before and after? And if yes, what is the effect on the output ph before and after the 2nd or 3rd chambers.

Sometimes it seems nice to have this or that but I always like to question real effectiveness and functionality.

If it is indeed alot better, then everyone should know about it and all calcium reactors should change their design to include a second chamber. I for one will want to build a second chamber for my own unit too.

[Joe_P]

The CO2 in the media should be adjusted to where it just manages to dissolve the media and not more than that. Otherwise, it would be pulling the ph too low. In order words, too much unreacted CO2 dissolved in the water.

That is why a taller reactor body will produce higher calc and dkh levels than a shorter one. Because higher bubble rate can be used....due to bigger surface area.

ain't the pH of the solution dependent on how much CO2 is injected??

therefore more CO2, means a lower pH and eventually better media dissolving??

I agree with the second statement that a taller reactor body will produce better results....

One question though, every individual system has different CA requirements... and I think it becomes pretty difficult to assess how much a reactor's height would be appropriate for a system..... (I know that the commercial reactors gives rating for tank sizes....) but that is merely jus a estimate as the amount of calcium demand per reef and that very much depends on livestock, sizes and their health ...

eg.. a 3 footer reef filled to the brink with SPS will need more CA/dkH compared with a 5 footer housing only LPS....

In fact due to space constraints, most reactors can't go really tall...... since most guys would like them installed into their cabinets...

so how tall can a reactor go???

So based on what you mentioned earlier...

are you suggesting that once a reactor is no longer efficient due to height and design, the reefer should change his unit to a taller one??? and if the next taller one doesn't, go even taller...

Therefore to counter the above mentioned, the most appropriate solution I can think of currently is to .....

1) modify the reactors to hold higher volume rated pumps to make it fludised..

therefore creating better surface area contact of media with chamber solution...

better efficiency....

2) increase the CO2 to get better effluent results coupled with second chambers to handle the depressed pH....

These are the 2 most feasible modes to venture to without creating higher cost...

of course if a reefer has more $$$ to burn, by all means get a larger unit...

Maybe you got a better suggestion here to offer me......

However, of course, with a second chamber, it allows me to have room for more mistakes in my adjustment for bubble count, ie help to buffer ph to 7....which theoretically is the point at which the ARM media will no longer dissolve.

exactly the reason why I design and build the hang on chambers...

With regard to your question, the ph of the chamber is only one of the factors influencing the output affluent. The design of the reactor, the media used and size are the main factors.

agree with the above statement quoted.

So in a nutshell, the statements and evaluation that you made are correct ... I agree with them.... however, when I started buildin my range of CRs...(and in the near future, other equipments), one continual factor that will always bug me is how can I help reefers to upgrade their current equip (to meet their reef requirements) without increasing cost....

In a ideal senario, getting better and larger and in this case taller stuff is the best way to go..... I would do that too if I have lots of $$$$....

But I think that is something that most of us would like to avoid.....