nft/spray style Medi Bud yellowing with droopy leaves no root growth some spots PICS

Hello all. This is currently my 4th grow and its my first with my new homemade system. The strain is Medi Bud. they are 2 weeks old. i always start my seeds off in a peat mix and switch them to netpots once they get a couple leaves and never had a problem with roots or growth in DWC. temp is 84 in room res stays 64-86f. also running CO2. ph is 5.6-6.0 using CWP 24-7 nutrient monitor. theyve been in hydro for 4 days now, before they were green like the luna haze(in the cup picture). now 4 days later theyre getting ugly. started with yellowing of the cotyledons then first leaves turned pale green. spots on the leaf tips with some curl up. i fig it overnuted it seeing how the soil mix was nuteless and they were fine so i switched them back to plain phd tap water with 2ml of voodoo juice to the 6gal res. now the leaves look all saggy as if overwatered but i have airstones and a 12inch water drop to the res with opt res temps for oxygen so i dont understand. before i switched them the roots were growing nicely now they dont seem to have grown in 3 days. using advanced nutrients sensi grow a&b b52 and voodoo juice in veg. any ideas on whats wrong?. also the stems seem kinda purpleish. i thought maybe i was keeping too much of the roots constantly wet so i put the pump on a 30 on 15 off.

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64-68f on the res temps lol not 86. and its not peat its MG seed starter soil i started them in

Wow nothing... Really. I noticed the backs of the yellow leaves are red purple