Depends. If your feeding pure water (no nutes) I would test theph once or twice to make sure your oh is on check then I wouldn't sweat it. BUT if your adding anything then yeah its a must.Do I need to Ph my Ro water for Clones ?
not sure about for to high for hempys, but thats some pretty hard waterMy tap water is like 300-400 ppm I was advised by a few people that it is to high to use in hempy's