PH and EC Relation

[omerizm]

GpsFrontier, Thanks for the help.

1. I'm preparing my own mix, all water soluble and used commonly in hydroponic systems. And I'm using a common formula, no problem there.
2. HCl
3. Tap water, not very good. EC measured at 0.6 I'm thinking about buyinh a RO unit.
4. Temp varies between 22-28 degrees celcius.
5. 25 gallons of water for about 50 heads of lettuce.
6. Lettuce, at different stages of growth from mature to seedlings.
7. My tester is accurate and calibrated, no problem there.
8. I adjust them to 6.0 and sometimes it jumps to 6.2-6.3 within a day.