Understood. I just figured I'd mention a cheaper source. Plus, it was good that Lad mentioned the sale.
I too have noticed the potassium (& other nutrient) levels are low in these types of things. But for fasting, I guess they're better than nothing, and one could supplement potassium in addition to this.
Here's a powder with a bit higher levels:
Hi-Lyte Keto K1000 Electrolyte Powder | Unflavored [I tried posting a link, but it didn't work.]
I like the convenience of a mixed electrolyte powder, although making your own with separate powders such as what Ladislaus posted does have the advantage of getting the proportions & amounts you want.