ADS1115 EC and PH cross interference on AI Channels

ASD1115 AI channel cross interference between EC (TDS Meter v1.0) and PH Probe (PH4502c)
Causing PH probe to go to max reading when EC probe is introduced into the tank
PH Calibration was checked as reasonable out of tank, and a reasonable PH measurement is made when EC is removed from the tank. Suspect EC probe leakage current gets into the PH Probe. Distancing the probes makes no difference. Placing the EC into an open plastic tube reduces the interference but still elevates the reading. Suspect there is no option but to have a separate ADS1115 for each signal?

Power isolation is this issue and is discussed in How to create a custom input with calibration using ADS1115 ADC and Gravity analog pH and EC sensors? - #29 by dookaloosy