Balanced Alkalinity/Calcium Tables

[Dr. Jim]

I know the general consensus is that it is not essential to perfectly match a particular calcium level with it's corresponding alkalinity measurement, but I'm wondering from where, and how, this table is derived....and, what is it's significance?

Also, even though it might be considered unnecessary to "chase numbers," would there be any benefit (even if just in theory) to actually having the calcium and alkalinity levels "match?"

 

[Moxtrain]

I find it interesting that pH isn't mentioned. That will change the balance numbers.

 

[Dr. Jim]

I find it interesting that pH isn't mentioned. That will change the balance numbers.

The table I posted above is from a D-D H2Ocean Salt brochure. I wonder if this table was tabulated for their particular salt that they claims mixes to pH 8.2-8.4?
I've seen other tables with slightly different calcium levels for a particular alkalinity level, so maybe the various tables were calculated based on different pH's??

 

[Randy Holmes-Farley]

The intent of balanced calcium and alkalinity IS NOT that they should ever be target levels.

What it means is that if you take normal seawater and add or subtract a balanced ratio of calcium or alkalinity (2.8 dKH of alkalinity for each 20 ppm of calcium), you can get to the values that are balanced.

That has some meaning, for example, in that if you start with normal seawater, you can get to any balanced levels by using a CaCO3/CO2 reactor, kalkwasser, or a two part with equal parts dosing, or by allowing corals to consume the alk and calcium.

So these are all balanced:

4.2 dKH 400 ppm calcium
7 dKH, 420 ppm
9.8 dKh, 440 ppm calcium
15.4 dKH, 480 ppm calcium

etc.

 

[Randy Holmes-Farley]

The table I posted above is from a D-D H2Ocean Salt brochure. I wonder if this table was tabulated for their particular salt that they claims mixes to pH 8.2-8.4?
I've seen other tables with slightly different calcium levels for a particular alkalinity level, so maybe the various tables were calculated based on different pH's??

pH wouldn't come into play.

 

[Dr. Jim]

The intent of balanced calcium and alkalinity IS NOT that they should ever be target levels.

What it means is that if you take normal seawater and add or subtract a balanced ratio of calcium or alkalinity (2.8 dKH of alkalinity for each 20 ppm of calcium), you can get to the values that are balanced.

That has some meaning, for example, in that if you start with normal seawater, you can get to any balanced levels by using a CaCO3/CO2 reactor, kalkwasser, or a two part with equal parts dosing, or by allowing corals to consume the alk and calcium.

So these are all balanced:

4.2 dKH 400 ppm calcium
7 dKH, 420 ppm
9.8 dKh, 440 ppm calcium
15.4 dKH, 480 ppm calcium

etc.

So by saying that "balanced calcium and alkalinity should not be target levels" are you suggesting that if the Alk is 7kH then Ca at 420 is NOT necessarily more desirable than 400 or 440 ppm (for maximum coral growth/health)?

4.2 dKH 400 ppm calcium
7 dKH, 420 ppm
9.8 dKh, 440 ppm calcium
15.4 dKH, 480 ppm calcium

I understand that "matching" the values is not essential...... just wondering if an "exact match" might be beneficial in any way.

Thank you!

 

[Randy Holmes-Farley]

So by saying that "balanced calcium and alkalinity should not be target levels" are you suggesting that if the Alk is 7kH then Ca at 420 is NOT necessarily more desirable than 400 or 440 ppm (for maximum coral growth/health)?

4.2 dKH 400 ppm calcium
7 dKH, 420 ppm
9.8 dKh, 440 ppm calcium
15.4 dKH, 480 ppm calcium

I understand that "matching" the values is not essential...... just wondering if an "exact match" might be beneficial in any way.

Thank you!

Right. Calcium level is quite unimportant to corals as long as its in the range of about 400 to 550 ppm.


And especially, " 4.2 dKH, 400 ppm calcium " may be perfectly balanced, but is not a good target.

 

[badger89]

I new to this am my Alk is at 151ppm and calcium is 479 how would i work out the balanced?

 

[Randy Holmes-Farley]

I new to this am my Alk is at 151ppm and calcium is 479 how would i work out the balanced?

See what I posted above:

"The intent of balanced calcium and alkalinity IS NOT that they should ever be target levels.:"

Your levels are fine and no changes are indicated for any reason.