Reef Chemistry Question of the Day #250 Precipitate on Dosing

[Randy Holmes-Farley]

Reef Chemistry Question of the Day #250

You just added a solution of sodium carbonate (washing soda) to your aquarium to boost alkalinity.

You noticed a white cloud forming immediately as the liquid hit the water.

What is that white material most likely to be?

A. Magnesium hydroxide
B. Sodium sulfate
C. Calcium hydroxide
D. Potassium carbonate

Good luck!



































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[kamike91]

Reef Chemistry Question of the Day #250

You just added a solution of sodium carbonate (washing soda) to your aquarium to boost alkalinity.

You noticed a white cloud forming immediately as the liquid hit the water.

What is that white material most likely to be?

A. Magnesium hydroxide
B. Sodium sulfate
C. Calcium hydroxide
D. Potassium carbonate

Good luck!



































.

With no reasoning...i want to say C

 

[dragon99]

A, but I don't remember why. Something about the pH spike locally.

 

[orr2003]

A or C? Doesnt it have something to do with the negatively charged ions in the Alk supp being attracted to the positive ions in the tank water?

 

[Daltrey]

The answer is A. Magnesium Hydroxide. Johnny, Tell em what I’ve won!

 

[MnFish1]

A MG hydroxide -

I dont think B or D would precipitate. (i.e. cause a cloud)
C - the cloud would not go away. (would form calcium carbonate - which would not re-dissolve)

 

[JonasRoman]

A

 

[Cory]

Pretty sure its A but im wondering if it needs to be higher ph than sodium carbonate is.