My pH is too High

[biloyp]

I am using General Hydroponics pH Down product and it is working really well. I do kep my pH meter in a solution as u sugested. Thanks for the advice , really appreciate it. Since I have brought my pH down, my lettuce is thriving, seems like lettuce likes the pH between 5-6. But my spinach seems to like pH around 6. I have learned so much doing this.