And yet another question about the relationship between salinity and calcium...

[Dom]

I understand that there is a ceiling for calcium based on salinity.

Currently, my calcium is at 380 with salinity at 33ppt.

So my question...

When I raise salinity back up to 35ppt, will calcium automatically come up or have I just raised the ceiling and made room for calcium increase through dosing?

 

[Randy Holmes-Farley Verified Community Expert]

Well, there's no ceiling, first of all.

If you add enough calcium chloride you can attain any level you want, although alkalinity will fall as you get higher and higher (like 800 ppm, etc.).

If you raise salinity by allowing evaporation or adding salts in the exact ratios currently present in the tank, going from 380 ppm at 33 ppt to 35 ppt will give 35/33 x 380 = 403 ppm.

 

[Dom]

Well, there's no ceiling, first of all.

If you add enough calcium chloride you can attain any level you want, although alkalinity will fall as you get higher and higher (like 800 ppm, etc.).

If you raise salinity by allowing evaporation or adding salts in the exact ratios currently present in the tank, going from 380 ppm at 33 ppt to 35 ppt will give 35/33 x 380 = 403 ppm.

So:

(33/35) = (380/x)... Cross multiply... gets you (13,300/33x)... solve for x...

x = 403.03

So using that ratio, is it correct to say:

(a calcium of 403 / salinity of 35ppt) = (target calcium of 440 / salinity of x)

Solving for x, tells me I should have a target salinity of 38ppt?

 

[Fishfinder]

You should have a target salinity of NSW 35ppt. And then add calcium if needed

 

[JimWelsh]

So:

(33/35) = (380/x)... Cross multiply... gets you (13,300/33x)... solve for x...

x = 403.03

So using that ratio, is it correct to say:

(a calcium of 403 / salinity of 35ppt) = (target calcium of 440 / salinity of x)

Solving for x, tells me I should have a target salinity of 38ppt?

38.2, but who's counting? But, then there is this:

You should have a target salinity of NSW 35ppt. And then add calcium if needed

 

[Dom]

38.2, but who's counting? But, then there is this:

My question was theoretical. I target 35ppt as a practice.

 

[Martin Kuhn]

Switching to not natural salinity isn’t what you should aim for.
Your tanks life stock prefers a salinity that it typically has in nature.

Racing salinity to high, besides the chemical effects of raising thus also Ca, Alk, Mg, Ka (potassium), is the physical effect.
Everything Inside the tank simply gets more floated upwards by the density difference

 

[Randy Holmes-Farley Verified Community Expert]

My question was theoretical. I target 35ppt as a practice.

If your goal is to raise calcium to 440 ppm from your current value by raising salinity, then yes, that is the correct way to calculate it.

In the end, this is a losing battle. The "target" salinity will keep rising each time you need more calcium.

You need to dose calcium chloride to maintain calcium.

 

[Dom]

Thank you to all!