I received a new Apex today and got every going with it. I calibrated the probes according to the instructions and I get a ph reading of 7.5. I am just not sure how it is so low when I have a hose from skimmer to the outside for fresh air, dose kalk through my ATO and run a light over my fuge to help with ph. With those three things it doesn't seem logical to me to have my ph so low. What do you think?