My ph some times goes up from 5.8 to 6.0 maybe 6.2 yet my ppm stays the same any ideas what this could be also some times it will stay at 5.8 but my ppm mite go up one light eg 1.6 to 1.8 in flower week 5 any 1 can give me some advice
Your ph will swing daily that's why it's good to check daily. When your ph rises and the ppm goes down that means your plants are taking in nutes. I believe it's a good when your ppm stays the same which means that you have everything dialed in.
5.5-5.8 is best for hydro its about solution density. If your nutes are being used at the same rate as the water in the solution, the TDS will remain the same while the use of the nutes increases the Ph (because the plant uses "negative" and releases "positive" resulting in a higher Ph) Please note that PPM is a measurement of TDS (ie my TDS is increasing from 400ppm to 420ppm)