Chemically speaking, this intro is misleading. There's absolutely no chemical or biological support for the statement that "alkalinity is harder on living things than is acidity". The fact that we can digest acidic foods in an organ specifically adapted for the job (our specially-lined stomachs) is hardly evidence that our bodies in general somehow prefer acidity over alkalinity. Would Mr. Eschenbach rather have stomach acid in his eye, or laundry soap? Both would do damage and hurt like hell.
the data he shows on his charts are scaled by days. I would be really worried if the acidity changed rapidly enough to cause damage in a month.
Anyone with a hot tub knows even a small change in the balance has serious consequences. Considering the ocean supports all life on Earth and we throw all our refuse into it, I'd say there's cause for concern.
