There was no white powder in the soil so it wasn't the carbonate. These
were tiny white crystals which I am pretty sure were salt. It was a 4
inch pot. I only usd the Aquafina brand water for 2 1/2 weeks and for
about a month I used distilled water. I thought the distilled water
would purify the soil which is why I was beginning tothink that maybe it
was the distilled water.