Water Ingredients Detrimental To Fermentation?

If this needs to be moved to another section, I understand.
I have found some 4 gallon water bottles at the local Costco business center. The water is reverse osmosis processed and then they add their electrolyte minerals consisting of magnesium, potassium and calcium. My question is will that potassium be detrimental to my fermentation of a mead or any other fermentable? I have emailed them as to the breakdown on their ingredients since their website (cactrus.com) and bottle labels list no such information. Even if the water is not ferment ready, I've got some nice 4 gallon BPA free carboys for slightly over $3.00 each.

Thanks for any help offered,
GTG

Potassium is not a problem. Yeast take it up to help maintain electrochemical balance as the pH of the must becomes acidic. The yeast need a variety of minerals to function their best.

Thanks for the info. I'll be happy to move forward with them then.
GTG