hey aim aim, yes, pH is very important but ppm's its somewhat the same rules. You gradually work your way up on strengths. With hydro however, you need to start feeding much earlier because it's inert and has no base nutrients in it.
All mediums bought should be rinsed off thoroughly, then let to soak in water and pH adjusted over 3 days.
if you want you can throw an airstone in the water or change it daily.
by the 3rd day the pH should stop shifting. I dump the water out and fill it 1 more time and pH adjust it, and then it's ready to be used. This is how we leech any extra salts out of the medium and also buffer it to our target pH
ph for both water being added to and the medium is 5.8, i go anywhere from 5.6-6.0 though, and just try to get 5.8 as best i can with the water going into it.
i start at a low ppm and then work my way up. If i burn the plant i back off.
i use coco and coco will lock out cal-mag so i add some with every watering
there is a method of doing 10% runoff and after you do a higher dose of nutrient, next watering you do 1/2 dose, and watering after you do 1/4 dose. after this you go a little stronger than the full dose, and keep repeating this until you max out. sometimes I will repeat my full dose, but I always do the runoff because it is key in preventing salt buildup. If you don't like the runoff method a leeching is recommended once a month. You just do 3x the medium size worth of water through it, to help decrease salinity.
so yes it's important to monitor pH and PPM's , but if you understand what to do it can be really easy, considering when i add my base nutes i add a teeny bit of pH down and i'm all set. Since i got the formula down it takes me about 5 minutes to get the water ready
almost forgot to add. I'm very suprised noone mentioned this thread
https://www.rollitup.org/drain-waste-hydro/546006-world-hempy.html