Kalk and Salt Mix

[ubiq]

I've read that using kalked RO/DI water for the salt mix is inadvisable, but I've never read why this is the case. This rule necessitates maintaining 3, rather than two, reservoirs. One for pure RO/DI for mixing, one for the salt mix used for water change, and one for the kalked RO/DI for topping off. It would be good to know, specifically, why kalked RO/DI shouldn't be used for the salt mix.

 

[Utubereefer]

Salt mix is set to mix at a certain ratio of alk/cal adding kalk to water before mixing salt is unnecessary. The reason for kalk is to replace the elements uptaken by the corals.

 

[Snoopy 67]

An old timer told me to use kalk in ALL my make up water.

 

[kaceyo]

An old timer told me to use kalk in ALL my make up water.

Do you think that means in all circumstances no matter what? Or under all circumstances in which normal fresh makeup water is being used?

 

[landlubber]

An old timer told me to use kalk in ALL my make up water.

hmm... i've heard it differently.
the version i know is to use Kalk only in top-off water.

 

[X-37B]

Put a small amount 1/8 teaspoon of kalk in 10g's of ro/di and test ph. It.will be over 10. Cant say I have ever heard of that recommendation or would I ever attempt it.

 

[Utubereefer]

hmm... i've heard it differently.
the version i know is to use Kalk only in top-off water.

I think they’re taking about putting it in before they mix water which I think is not needed. I do dose kalk using a kalk reactor

 

[X-37B]

I think they’re taking about putting it in before they mix water which I think is not needed. I do dose kalk using a kalk reactor

They specifically mentioned why is it not advised to mix it with the salt mix.

 

[Utubereefer]

I don’t read so well

 

[landlubber]

Do you think that means in all circumstances no matter what? Or under all circumstances in which normal fresh makeup water is being used?

this part is where my questions come up as well. adding kalk immediately like this opens the door to a massive surge in pH which is why people tend to add slowly through top off water.

 

[Randy Holmes-Farley Verified Community Expert]

They specifically mentioned why is it not advised to mix it with the salt mix.

And they are quite right.

Why would you? What would you be trying to accomplish that is not better attained other ways?


It adds alk and calcium and raises pH a lot (often to the point of precipitating magnesium hydroxide and possibly calcium carbonate.

 

[Randy Holmes-Farley Verified Community Expert]

hmm... i've heard it differently.
the version i know is to use Kalk only in top-off water.

Those two sentences have the same meaning. top off water and make up water are the same: evaporation replacement, not making up new saltwater.

 

[landlubber]

Those two sentences have the same meaning. top off water and make up water are the same: evaporation replacement, not making up new saltwater.

ah, i suppose the confusion sits with saying "ALL make up water" which to me implies adding salt in my mind. i've never heard it mentioned that way, my bad.
its always been either RODI or NSW in my reefing career.

 

[Randy Holmes-Farley Verified Community Expert]

ah, i suppose the confusion sits with saying "ALL make up water" which to me implies adding salt in my mind. i've never heard it mentioned that way, my bad.
its always been either RODI or NSW in my reefing career.

Calcium hydroxide and oxide should only be ever added to fresh water. Some folks add a slurry of particles to the aquarium, and that can be OK (with risks), but it's not a good plan to add to new salt water.

That fresh water can be used to replace evaporation and supplement calcium and alkalinity.

 

[Snoopy 67]

Thanks for the clarification Randy, right on.