Has anyone had their low range phos checker go bad? I tested today and my first reading was .14 and I knew that couldn’t be, so I grabbed my other vial and did a quick test. It came back at .1. The next three quick tests came back .02. I have never had it read that wide of a range. So I have no clue what my PO4 is right now. Anyone experience this? And is the ultra low checker more reliable?