Did you spray this solution on the leaves? Hmmmm......that could do it I suppose but I'm not positive.....if it IS due to that it should drop back to normal (and what I mean by that is actually stop rising) within in a day or two. If it stays the same or the ph rises even more quckly etc....you may have a different problem.

Do you use H202 or a "zyme" product for your roots?