X1= Gals liquid in system

X2= gals liquid being introduced

Y1= current ph in system

Y2= ph being introduced to the system

Z1= rate of change

X1-x2=x3

Y1-y2=y3

Y3/x3= z1

(Z1 * x2) +/- y1 = adjusted ph of the entire system if x1 & x2 are combined