ther fine. GK is on the money...You were not watering them enough and the roots were drying. I run my similar homemade drip system lights on+drip 1 hour on/off for 15 minutes, all during lights on. when lights are off, I drip 15minuteson/off 1 hour...good luck.

p.s. run your nutes without grow...after veg.
use the 5ml per gallon value of calmag+
diamond nectar...I don;t use, so follow bottle directions toward the lighter side...and buy some hygrozyme or sensizyme to replace the epsom salts...although I have no problem with epsom salts. I love Hygrozyme.

you got a good start. peace