mixing mag. cloride & mag. sulfate

[outssider]

I have brs Mag. sulfate and Mag. cloride. Is it possible to mix the two in their dry form and store it ??

[disc1]

I have brs Mag. sulfate and Mag. cloride. Is it possible to mix the two in their dry form and store it ??

Yes. But it is best to mix up the amount you want to dissolve at once. If you were to mix up say ten pounds and it isn't perfectly homogenous then when you go in for a cup to dissolve it might not be the right mix. For example it might settle or something.

[MikeYQM]

Actually, I was under the impression that they should be dissolved separately in RODI water then mix the two solutions to complete the additive.

[rayjay]

I weight out each and put them in the bottles and then add the water.
I don't mix before I'm going to make solutions as I see no advantage to doing so.

[bertoni]

Dissolving the two together is fine. I'm not sure why anyone would suggest dissolving them separately.

I agree that settling is a problem. You could make baggies containing enough for a 5g container, for example, and store them that way. Then you could just dump an entire container of the mix into 5g of water.

[MikeYQM]

"Note that combining the two materials in solution can result in some precipitation of calcium sulfate (calcium and sulfate are impurities in the MAG flake and the Epsom salts, respectively. To assure yourself that the two materials have fully dissolved, dissolve each separately in some freshwater before combining them. Some calcium sulfate precipitation is acceptable, and it is okay to let the solids get into the aquarium, assuming you can dose in a way that prevents them from landing on delicate organisms."

-Randy Holmes-Farley, Do-It-Yourself Magnesium Supplements
for the Reef Aquarium

[bertoni]

I see, you might want to check for impurities. Well, that makes some sense. I'm not sure I'd bother at this point, given the experience we have with the DIY formulae, but it could help detect a bad batch of chemicals.