Kalk and Salt Mix

ubiq · Dec 21, 2021

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 · Dec 21, 2021

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 · Dec 21, 2021

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

kaceyo · Dec 21, 2021

Snoopy 67 said:
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 · Dec 21, 2021

Snoopy 67 said:
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 · Dec 21, 2021

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 · Dec 21, 2021

landlubber said:
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 · Dec 21, 2021

Utubereefer said:
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 · Dec 21, 2021

I don’t read so well

landlubber · Dec 21, 2021

kaceyo said:
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 · Dec 21, 2021

90's reefer said:
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 · Dec 21, 2021

landlubber said:
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 · Dec 21, 2021

Randy Holmes-Farley said:
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 · Dec 21, 2021

landlubber said:
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.