Dramatic pH drop in filtered H2O?

[khyberkitsune]

That seems like a big drop,and to 5.8 seems even stranger.You are using a meter right? not some test papar strips. those papers are so EASILY contaminated.

What was your last filter puting out for Ph? Let us know what it does after 20-30 gal of use.

Daddy

I use liquid reagents for pH testing. I don't use paper, and meters require constant calibration.

I wasn't using ANY filter, at all, ever, until now.