Q: Relationship between Salinity and Calcium/Alkalinity

[grim]

Mr. Chemistry,

What is the relationship, if any, between the salinity of salt water and its capabilities of 'holding other stuff'. Does a lower salinity solution have a higher 'other-stuff-holding-capability' than a higher salinity solution? I know that a higher salinity solution carries less oxygen (is this correct?), but what about calcium/alkalinity, etc?

In case your wondering where this stems from, I tested my water with a refractometer yesterday and found my salinity to be 38ppm (after calibration). I've had problems in the past raising calcium and alkalinity (and holding them there) and am wondering if this could possibly be the reason for it. I'm in the process of lowering my salinity to 35ppm, but have not yet had time to measure cal/alk or supplement any more than my usual dose of B-Ionic. I'm guessing since I diluted the solution, I'll need to make up for some cal/alk (likely I'll be even lower than usual at this point).

Thanks Mr. Wizard!
-jb

[Randy Holmes-Farley]

Seawater has a much higher ability to maintain the combination of calcium and alkalinity. That is, calcium carbonate is much more likely to precipitate from freshwater (or low salinity seawater) than it is from full strength seawater.


Higher than full strength seawater (at least in the range that you mention) is not lilkely to reduce the ability to hold calicum and alkalinity.

Low magnesium and high pH will increase the precipitation of CaCO3.

[grim]

Thanks for the info! I'll look at my magnesium levels to see if that provides any insight.

Thanks!
jb

[Randy Holmes-Farley]

You're welcome.:)