I’m currently lost in this sauce now to. My spread is large. Makes me wonder if my conductivity is low? I have calibrated Hanna to it’s packets and it also reads dead on 1.026 for the refract cal solution, AccuBrate. Refractometer also calibrated to same AccuBrate. Both read 0 at RODI FWIW. Tank water reads 1.025 for refrac and 1.021 for Hanna, what the heck? That seems outside the accuracy’s...hence is there something else going on in the chemistry? Alk is 6.8, ph is 7.8.