pH of KALK too high?

[Mohammed]

Hi Guys,

I recently acquired a SAGA pH pen and have been monitoring my pH and it ranges between 8.5 to 8.6 at times having rarely measured it below this. I have calibrated with the two points.

On testing my KALK it was a pH of 13.9.

From Randy's article on "What Your Grandmother Never Told You About Lime "

Limewater that is saturated with calcium hydroxide has a pH of 12.54 at 25ºC. It is actually recognized as a secondary pH standard. The pH is substantially higher at lower temperature (12.627 at 20ºC and 13.00 at 10ºC), and lower at higher temperature (12.289 at 30ºC; 11.984 at 40ºC).

I suspect my RO temp to be about 20ºC.

I'm currently adding 8 tsp in 20 lt (5.28gal). With the max saturation at 10.5 tsp in 20 lt. I'm a little under the max saturation and yet my kalk measures a pH of 13.9.

My consumption has increased and I want to get to max saturation but not at the expense of increasing pH.

What could be the possible cause for this and should I be concerned?

Here's the CoA of the Lab Grade Kalk I use from a specialist chem company

Parameters Limits Results

Description Powder Powder
Colour White White
Identification Conforms Conforms
Carbonate (CO3) Conforms Conforms
Flouride (F) Max 0.005% <0.005%
Acid-insoluble substances Max 0.5% <0.5%
Arsenic(As) Max 0.0003% <0.0003%
Lead (Pb) Max 0.0002% <0.0002%
Magnesium and Alkali Salts Max 4.8% <4.8%
Assay Ca(OH)2 95.0-100.5% 98.5%

Thanks

 

[ClownNut]

Hi Guys,

I recently acquired a SAGA pH pen and have been monitoring my pH and it ranges between 8.5 to 8.6 at times having rarely measured it below this. I have calibrated with the two points.

On testing my KALK it was a pH of 13.9.

From Randy's article on "What Your Grandmother Never Told You About Lime "

Limewater that is saturated with calcium hydroxide has a pH of 12.54 at 25ºC. It is actually recognized as a secondary pH standard. The pH is substantially higher at lower temperature (12.627 at 20ºC and 13.00 at 10ºC), and lower at higher temperature (12.289 at 30ºC; 11.984 at 40ºC).

I suspect my RO temp to be about 20ºC.

I'm currently adding 8 tsp in 20 lt (5.28gal). With the max saturation at 10.5 tsp in 20 lt. I'm a little under the max saturation and yet my kalk measures a pH of 13.9.

My consumption has increased and I want to get to max saturation but not at the expense of increasing pH.

What could be the possible cause for this and should I be concerned?

Here's the CoA of the Lab Grade Kalk I use from a specialist chem company

Parameters Limits Results

Description Powder Powder
Colour White White
Identification Conforms Conforms
Carbonate (CO3) Conforms Conforms
Flouride (F) Max 0.005% <0.005%
Acid-insoluble substances Max 0.5% <0.5%
Arsenic(As) Max 0.0003% <0.0003%
Lead (Pb) Max 0.0002% <0.0002%
Magnesium and Alkali Salts Max 4.8% <4.8%
Assay Ca(OH)2 95.0-100.5% 98.5%

Thanks

did you calibrate the pH pen when you got it?

 

[ClownNut]

Hi Guys,

I recently acquired a SAGA pH pen and have been monitoring my pH and it ranges between 8.5 to 8.6 at times having rarely measured it below this. I have calibrated with the two points.

On testing my KALK it was a pH of 13.9.

From Randy's article on "What Your Grandmother Never Told You About Lime "

Limewater that is saturated with calcium hydroxide has a pH of 12.54 at 25ºC. It is actually recognized as a secondary pH standard. The pH is substantially higher at lower temperature (12.627 at 20ºC and 13.00 at 10ºC), and lower at higher temperature (12.289 at 30ºC; 11.984 at 40ºC).

I suspect my RO temp to be about 20ºC.

I'm currently adding 8 tsp in 20 lt (5.28gal). With the max saturation at 10.5 tsp in 20 lt. I'm a little under the max saturation and yet my kalk measures a pH of 13.9.

My consumption has increased and I want to get to max saturation but not at the expense of increasing pH.

What could be the possible cause for this and should I be concerned?

Here's the CoA of the Lab Grade Kalk I use from a specialist chem company

Parameters Limits Results

Description Powder Powder
Colour White White
Identification Conforms Conforms
Carbonate (CO3) Conforms Conforms
Flouride (F) Max 0.005% <0.005%
Acid-insoluble substances Max 0.5% <0.5%
Arsenic(As) Max 0.0003% <0.0003%
Lead (Pb) Max 0.0002% <0.0002%
Magnesium and Alkali Salts Max 4.8% <4.8%
Assay Ca(OH)2 95.0-100.5% 98.5%

Thanks

:eek1::eek1::eek1:

 

[Mohammed]

did you calibrate the pH pen when you got it?

Yes i did.

 

[bertoni]

The pH measurement will be accurate at best between the pH points of calibration, typically 7 and 10 pH, so I would ignore the reading for the Kalkwasser. I always got odd readings, too.

Those pH levels are safe, so I would avoid anything drastic, but better aeration probably will lower the pH a bit, if the readings are accurate. We see a lot of problems with pH measurements, though. Does the tank have a skimmer? If so, is it in need of cleaning or turning? Also, a bit of motion on water surfaces can help with keeping films from interfering with aeration. It's rare for that to be a problem, but it's very easy to check.

 

[Mohammed]

Ok kewl,

Surprisingly, i was going to clean the skimmer and pump and vwnt the intake outside the cabinet to a neaby window

 

[bertoni]

Cleaning the skimmer might help a lot. When they get detuned, for whatever reason, aeration can drop off a lot.