Kalkwasser Reactor

[Roloilly]

I've been reading that the best way to measure kalkwasser saturation is with a conductivity meter. I'm thinking of purchasing an Apex controller. What probe would be able to make that measurement ORP probe or the saltlinty probe? I would like to put that on the top of the reactor to measure saturation and to know when it needs replenishing with kalkwasser.

 

[Montiman]

You will need to use the salinity probe as it is what measures conductivity.

 

[Roloilly]

You will need to use the salinity probe as it is what measures conductivity.

What should the readings be for full saturation and for when it requires replenishing.

 

[ZombieEngineer]

What should the readings be for full saturation and for when it requires replenishing.

About 660 ppm fully saturated (10mS/cm2).

I would just make a new batch, measure the conductivity and then alert yourself at like 50-75% what "normal" is.

 

[Roloilly]

About 660 ppm fully saturated (10mS/cm2).

I would just make a new batch, measure the conductivity and then alert yourself at like 50-75% what "normal" is.

Would thus reading be possible using a saltlinty probe from the Apex using there controller?

 

[SunnyX]

Excuse my ignorance, but why would you need to know the saturation point of the kalkwasser, or even measure it? Can you not simply add a fixed amount of kalkwasser at regular intervals based on evaporation and usage? With an abundant amount of kalk media in the reactor you will always be certain to have saturation.

I have employed a kalk reactor for many years now, 20+ years, and the simplest Method of of dosing is as I described above.

On my current aquarium I have a Tunze Kalkreactor(Love it!) and keep about 4” of kalk media in it. Once every two weeks I add more kalk media and that’s it.

I will periodically check the effluent to ensure that the kalk is at saturation. So long and the ph coming out of the reactor is 11.5-12 I am happy.

-Sonny

 

[ZombieEngineer]

Would thus reading be possible using a saltlinty probe from the Apex using there controller?

Yes. If you're using the built in port and not a PM2, the resolution may be too low to be reliable (normal would be 0.6ish need filled would be 0.3ish). With a PM2, the range is adjustable so the 660ppm is easier to measure.

I personally wouldn't even bother cause it's pretty easy to make sure a kalk reactor is topped off so I don'tthink the cost/benefit is worthwhile for me. If you've got money burning a hole in your pocket though, the salinity probe would definitely work and is an interesting automation.

 

[BroccoliFarmer]

I just Apex second PH meter to measure the PH of my Kalk Stirrer. 12.0 and I know it is saturated!!

 

[Randy Holmes-Farley Verified Community Expert]

Would thus reading be possible using a saltlinty probe from the Apex using there controller?

I do not know how well it reads at the low end. An apex user who has tried it will need to respond. Not all conductivity meters can.

 

[Randy Holmes-Farley Verified Community Expert]

I just Apex second PH meter to measure the PH of my Kalk Stirrer. 12.0 and I know it is saturated!!

Well, if it really is exactly pH 12, it is far below saturation. pH is a very crude measure (0.3 pH units difference is a factor of ~2 in potency), but saturation at 25 deg C is 12.54, and pH 12.00 implies only 29% saturated.

 

[BroccoliFarmer]

Well, if it really is exactly pH 12, it is far below saturation. pH is a very crude measure (0.3 pH units difference is a factor of ~2 in potency), but saturation at 25 deg C is 12.54, and pH 12.00 implies only 29% saturated.

Fluctuates from 12 to 12.2 based upon my stirring schedule

 

[Randy Holmes-Farley Verified Community Expert]

Fluctuates from 12 to 12.2 based upon my stirring schedule

It probably is not calibrated for accurate measurement at pH that high, but you can check it by placing the probe in truly saturated kalkwasser (say, 2 tablespoons calcium hydroxide in a cup of RO/DI) and measure that pH. Then look at the difference between it and the reactor effluent.

 

[ZombieEngineer]

I do not know how well it reads at the low end. An apex user who has tried it will need to respond. Not all conductivity meters can.

Built in with the head unit, not great. Resolution on that is 0.1ppt 0-45ppt.

With the PM2 using the medium range it can measure 0-8.50 mS/cm2 at a resolution of 0.01mS/cm2. I have tried the low range (0-0.85mS) to check my RODI water and it is very sensitive on the low end. Never tried medium range.

Neither are ideal since saturated is more than full scale reading on the medium range and the resolution sucks on the high range.

pH could maybe be another alternative, but I believe the short circuit reading on that probe was between 11 and 12 if I remember correctly. Does pH drop substantially when not fully saturated? I vaguely recall it being pretty close to 12 even at half saturation. If I did my math right, I think it's 12.1 half saturation, 11.8 quarter saturation. If that's right, the probe can't reliably tell saturation level from pH.

 

[Roloilly]

Built in with the head unit, not great. Resolution on that is 0.1ppt 0-45ppt.

With the PM2 using the medium range it can measure 0-8.50 mS/cm2 at a resolution of 0.01mS/cm2. I have tried the low range (0-0.85mS) to check my RODI water and it is very sensitive on the low end. Never tried medium range.

Neither are ideal since saturated is more than full scale reading on the medium range and the resolution sucks on the high range.

pH could maybe be another alternative, but I believe the short circuit reading on that probe was between 11 and 12 if I remember correctly. Does pH drop substantially when not fully saturated? I vaguely recall it being pretty close to 12 even at half saturation. If I did my math right, I think it's 12.1 half saturation, 11.8 quarter saturation. If that's right, the probe can't reliably tell saturation level from pH.

 

[Roloilly]

Thanking everyone for your help. One more question. I have a container from BRS of kalkwasser that I've had for over 5 years does this have a self life?

 

[ZombieEngineer]

Thanking everyone for your help. One more question. I have a container from BRS of kalkwasser that I've had for over 5 years does this have a self life?

No shelf life. Can last for decades.

 

[Randy Holmes-Farley Verified Community Expert]

CO2 can enter slowly and convert it into calcium carbonate (which is mostly useless but won’t hurt the tank). You may just need to add more than expected to attain a specific potency.