I really should calibrate the ph pen with some solution, I'll make a point to be certain it is correct. I do feel it is at least accurate to .1 in the mean time.
You're right about the kalkwasser, not being full strength, DOH!
My green slimer acro is starting to turn white up the side not facing the powerhead. Could any of this be related to the ph/alk issue?
Thanks again all MUCH appreciated
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