Two thoughts. First Mother Nature is always more variable than we think. Dwight and I like to find the patterns in stuff, but all the factors involved just result in exceptions, at least occasionally.
Second, lowest DO ever at Dwight's pond is still darn good shape. No concern whatsoever at 6 ppm. Your pond appears to have the capacity to handle the oxygen demand from those decaying plants. Let's see what next week brings.
