My PH has been like this for at least as long as I have had my controller and get a reading 24/7. I guess people who don't use a PH probe should try to do their PH testing at about the same time of day so it's a consistent standard they are comparing.flamron That is almost exactly my swing for pH. I was having some major issues, mostly Alk & Ca issues, but I've gotten that corrected, and am starting to see growth again with the pieces that I didn't lose. FWIW, my pH swing never changed throughout all of my battle, and is still 8.1-8.37 depending on the time of day.