okay so day 1 : saw the roots coming out of the disk so i put them in the cages with beads (put the beads in acidic water for like half a day to make them less alcaline).
day 4 : saw gorilla auto white roots (because probably its the most humid (stagnant water below it). the others had no white roots yet despite having leaves at same stage as gorilla auto. I sprayed for humidity like only 2 a day. maybe should have done more often.
day 5 : okay now really urgent to get this on the system (couldnt do it at day 4 because too busy). so put the whole installation up. and charged only the 10 liters of water (tap water with high EC already like 0.76 and 7.63 of PH) with 5 ml / l of root juice.

to handle PH : god damn I put like 60 drops of acid per 5 liter this night to bring it like around 6
Was worried about temperature but everythings good. around 23 during light and 19 during night. with open windows.

day 6 : goddam the ph raises to 7.2 so I put another 20 drops per 5 liter (total : 80 drops per 5 liter). lets see how this goes
also since there are 2 levels of real leaves at least (some start 3), I put half dose of biogrow (0.5 ml / l)
EC also very high : 1.2
for heat : trying close windows because too cold

So problem here : high EC and high Ph

Day 7 : because I put tap water to regulate too low pH, now the problem seem to be the origin of the ph fluctuating always towards high even after 48 hours. (did it on day 6 , monday evening still fluctuating)