I think I already know what you will say, but have to ask. I bought this used, hint hint. I have lab grade probes, Ph and orp. The Ph is way off from the test kit. When calibrating in the Coralife 7 and 10 solution, I get a reading of 7.1 to 7.4 when complete. That is when I put the probe back into the sump. I check with my test kit, 2 months old, and get readings around 8 to 8.3. I am thinking it is time for a new probe. When I recieved the ACII the probes were dry, not in any liquid. I have calibrated and re-calibrated, but never even close to what the test kit shows. Sound like it is time for new probes?
