What's wrong with my clones ? HELP

My dosidos clones from PURPLE CITY GENETICS are yellowing and tips are looking burnt ? I have them under Four 4ft T8's 4100K 40w lights. I also put like 2 drops of root excelurator into a Nestle Pure Life water bottle. I've been feeding with that brand water. Any one have any idea what can be wrong with them?

high ph

could be those damned Nestle bottles, notorious for yellowing clones....
they need real nutrients, without real food they will yellow, and the tips will dry out first, then they will die.

have they actually rooted yet, if not dont give them nutes