Importantly, Costco also sells Kirkland Signature natural spring water ... so those who are wary of fluoride should double-check that the water bottles at their Costco are labeled as "purified ...

A Costco customer claims she discovered the pH isn’t as advertised in the retailer’s bottled alkaline water. In a video with over 11,000 views, TikToker @vianht05 holds up a bottle of Kirkland ...

A measure of how effectively the filter removed flavor taints, along with the resulting odor taints, that CR added to plain water with minimal intrinsic flavor and odor (the "control" water).