Magnesium chloride flake

[t5Nitro]

Wondering if anyone has used alternate products other than Dead Sea's Mag Flake for DIY mag supplement?

Was looking at this:
Amazon product ASIN B0BZ9L757P
Let me know what you guys are using or what you think of the above product. Looks like 100% MgCl₂ from what I can tell.

Screen shot from a customer review:

My third option is to buy the BRS stuff since that's readily available.

 

[t5Nitro]

Or perhaps this one is easy to find
https://www.acehardware.com/departments/lawn-and-garden/snow-removal-and-equipment/ice-melt/7208846

 

[Randy Holmes-Farley Verified Community Expert]

I do not know if it is adequately pure. One concern with such materials is ammonia. If you try an off brand, I’d measure it for ammonia.9.

 

[t5Nitro]

Ah bummer -- I read a handful of posts of people using it so figured it might be alright. I purchased mg sulfate usp from Target and the safe step 8300 from the local hardware store.

Has anyone else found a good source of pure magnesium chloride flake? Find it hard to believe you have to buy what BRS is selling. I'm sure they don't make it lol!