When my plants are that young i don't use nutes or if i do i use a seedling one part nute in low amounts.

can you post a pic of your set up ie How far the lights are from the plants/what lights your using.

also how good are your bubbles? if youve using them airstones for a grow before they get blocked up.

If your ph has been 6 or so this whole time it's not that and with rootroit cubes there more then enough nute for a seedling.

I would say the waters not aired enough to keep a seedlings roots misted above the water level and/or the lights too hot on the plants.

good luck

btw if ur using hard tapwater ( sounds like it ) not RO or soft water u souldnt need cal/mag at that young if not at all.
jimm1432 Reviewed by jimm1432 on . so lets try this DWC thing agen. cuz I got to get it down some day. 3 dank seeds that came from some dank buds. they seem to be takeing for ever to sprout. and the clone I had looks like death.but she alwase had ph tested tap water to grow in. ph is 5.9-6.0 the ferts I am gunna be using is. for veg is gunna be botanicare pure blend pro hydro-organic accelerated vegetative flrmula 3-1.5-4. and for flowering I am gunna be useing the general hydroponics florabloom 0-5-4. Rating: 5