Just thought I would get the forums opinion. I ordered the PH meter with my TF-100 kit. I calibrated it per instructions. The meter reads my pool water at 6.9 and my TF100 says more like 8.0. I also checked it with my ColorQ pro which I use for a back up. It says 8.0 Why would the meter read correct in the buffer solution but be completely off in the pool water? Any ideas?