Issues with alkalinity and calcium.

[GillMeister]

I'm dosing ATI Essentials Pro to maintain Ca and alk. I also dose kalkwasser at night. I would assume if I'm dosing the right amount my CA and alk levels would remain equal.

The are not. Each day I have to dose extra soda ash to bring my alk up 0.2 dkh. My calcium is relatively stable at 400ppm.

Why the extra consumption of alk? I don't get it.

 

[vetteguy53081]

I'm dosing ATI Essentials Pro to maintain Ca and alk. I also dose kalkwasser at night. I would assume if I'm dosing the right amount my CA and alk levels would remain equal.

The are not. Each day I have to dose extra soda ash to bring my alk up 0.2 dkh. My calcium is relatively stable at 400ppm.

Why the extra consumption of alk? I don't get it.

There has to be a balance as they work hand in hand
Too much ca will affect alk and ph
What test kits are you using?

 

[GillMeister]

Red Sea for both. I test alk daily to make sure i understand the consumption rate.

 

[Tamberav]

They are hobby grade test kits so the numbers are not exact. Their advertised accuracy shows 0.14 alk so it could be that much higher or lower in value in a proper working kit with no human error.

 

[Randy Holmes-Farley Verified Community Expert]

It’s fine to dose slightly unequally, but an extra 0.2 dKH is very small. If you dosed both equally to maintain alk, the extra calcium is only 1.4 ppm of calcium and it would take at least two weeks to reliably see that with a hobby kit.

 

[nereefpat]

Just to clarify, you want to dose both equally based on alkalinity consumption.

 

[GillMeister]

It’s fine to dose slightly unequally, but an extra 0.2 dKH is very small. If you dosed both equally to maintain alk, the extra calcium is only 1.4 ppm of calcium and it would take at least two weeks to reliably see that with a hobby kit.

It's .2 per day, almost 1.5 over the course of a week.

 

[GillMeister]

Just to clarify, you want to dose both equally based on alkalinity consumption.

I am dosing equal parts, but having to dose a little extra alk to keep the alk level from declining more rapidly than my calcium.
Coincidentally my calcium was a little lower this morning so I will have to up my dosing.

 

[nereefpat]

It's .2 per day, almost 1.5 over the course of a week.

Right, 1.5 dKH per week will only equate to about 10 ppm in Ca usage. Our Ca test kits are +/- 20ppm, at best. The extra calcium, if there is any, will get lost in the noise (standard error) of the test kit.

I am dosing equal parts, but having to dose a little extra alk to keep the alk level from declining more rapidly than my calcium.
Coincidentally my calcium was a little lower this morning so I will have to up my dosing.

Dosing equal parts, but dosing a little extra alk, isn't dosing equal parts. Dose both volumes equally, based on how much alk you need to dose.

 

[GillMeister]

Right, 1.5 dKH per week will only equate to about 10 ppm in Ca usage. Our Ca test kits are +/- 20ppm, at best. The extra calcium, if there is any, will get lost in the noise (standard error) of the test kit.


Dosing equal parts, but dosing a little extra alk, isn't dosing equal parts. Dose both volumes equally, based on how much alk you need to dose.

I might not be making myself clear.

I dose ATI Essentials Pro. Equal parts 1 and 2. This additive is supposed to have the right ratio of Ca and alk.

I dose kalk at night. Should have the correct ratio of Ca and alk.

I have to dose EXTRA soda ash to maintain alk relative to Ca. It appears my consumption of alk is higher. There is nothing wrong with my dosing.

It's not a problem. I'm just trying to understand why.

 

[nereefpat]

I might not be making myself clear.

I dose ATI Essentials Pro. Equal parts 1 and 2. This additive is supposed to have the right ratio of Ca and alk.

I dose kalk at night. Should have the correct ratio of Ca and alk.

I have to dose EXTRA soda ash to maintain alk relative to Ca. It appears my consumption of alk is higher. There is nothing wrong with my dosing.

It's not a problem. I'm just trying to understand why.

I understand you. I would dose more of both parts 1 & 2, until you are matching the consumption of alk.

 

[Randy Holmes-Farley Verified Community Expert]

It's .2 per day, almost 1.5 over the course of a week.

yes, I understood. That’s very small and it would take 2 weeks to see the balanced calcium change with a kit.

 

[Randy Holmes-Farley Verified Community Expert]

I might not be making myself clear.

I dose ATI Essentials Pro. Equal parts 1 and 2. This additive is supposed to have the right ratio of Ca and alk.

I dose kalk at night. Should have the correct ratio of Ca and alk.

I have to dose EXTRA soda ash to maintain alk relative to Ca. It appears my consumption of alk is higher. There is nothing wrong with my dosing.

It's not a problem. I'm just trying to understand why.

I think if you dosed both parts evenly to match alk demand, you’d hardly notice the calcium rise. That’s the point we are making.

But kalk is part of the issue because it is not exactly balanced. kalkwasser is oversupplying calcium relative to alkalinity. It adds 20 ppm calcium for each 2.8 dKH of alk, but calcification only uses 18-20 ppm calcium per 2.8 dKH because magnesium and strontium get into the forming calcium carbonate in place of some of the calcium.

 

[GillMeister]

I think if you dosed both parts evenly to match alk demand, you’d hardly notice the calcium rise. That’s the point we are making.

But kalk is part of the issue because it is not exactly balanced. kalkwasser is oversupplying calcium relative to alkalinity. It adds 20 ppm calcium for each 2.8 dKH of alk, but calcification only uses 18-20 ppm calcium per 2.8 dKH because magnesium and strontium get into the firming calcium carbonate in place of some of the calcium.

HA! THIS!!! This is the answer I was missing. Thank you Randy. You are helpful as always.