Evaporation of NSW

[marke]

When NSW gets evaporated to make seasalt---does it affect the ions left in the salt powders. Will Mg, Ca etc be the same as the original nsw.

 

[EMeyer]

The different salts precipitate out at different rates, so my understanding is that no, pure evaporated sea salts will have a different composition than normal seawater. I dont believe any salt manufacturer sells pure evaporated salts for that reason. I think they all add stuff back in to restore somewhat-correct-ish chemistry.

 

[Randy Holmes-Farley Verified Community Expert]

A few big issues preclude drying out seawater to make a dry salt mix for reefs. The biggest is precipitation and calcium and magnesium carbonate, greatly depleting alk, depleting calcium a bit, and mostly leaving magnesium ok since it is so high to begin with.

the other concern is precipitation of trace elements, such as iron, onto and into that calcium carbonate. Most other things will redissolve.

Millero in chemical Oceanogrsohy shows what precipitates at what level of drying if you are interested. There is a steady progression of changing precipitates from least soluble to lastly, the most soluble.

 

[marke]

Thanks Randy---Just bought the 2nd edition book on amazon used.

 

[Randy Holmes-Farley Verified Community Expert]

Great!

Happy Reefing