PH should be 5.8 to 6.2. other wise you start nute lock out.

PPM's can depend on water, nutes and add ons. I have got mine close to 200 in the past but some plant can't stand it. During flower about 800 ppm's with R/O water. Then calmag and any add ons will bring it up to 1200 ppm's or so.

Hydro water temp should be kept at 68 to 72. Best point of oxy levels in water.