I have a Catalina Swim Spa 675gallons. This mornings test: Hardness 210ppm, ph 7.5, TA 70ppm. I use dichlor for my sanitizer.
Using muriatic acid to lower ph and sodium bicarbonate to raise alkalinity. If I add enough sod bicarb to get alkalinity above 80ppm my ph goes to 7.8. Then I add enough muriatic acid to get the ph back down to 7.5 and the alkalinity drops to 70. How can I get the ph in the 7.2-7.5 and alkalinity in the 80-120ppm at the same time?