Error lvalue required as left operand of assignment for hydroponic sensors

The problem is that PH4 and PH7 are already defined in some files included by the compiler

/home/test/.arduino15/packages/arduino/tools/avr-gcc/7.3.0-atmel3.6.1-arduino7/avr/include/avr/iomxx0_1.h:1113:0: note: this is the location of the previous definition
 # define PH4    4