If your grow rocks are already turning white and you're only at the seedling stage I'll bet you have hard water. Check your ppm.

Newbs+hydro=trouble.
Newbs+dirt=buds.
No offense I hope, but really dirt is such an easy way to get to know growing.
stinkyattic Reviewed by stinkyattic on . 1st Hydro attempt. Frazzled seedling!! HELP. Hi I've just checked my new hydro setup, and the poor little bugger has been burnt to a crisp! The clay pebbles used to fill the tray, the tops have turned white! I'm so confused. I'm using the drip ring method, with the water just trickling out of the underside holes on the ring. Should it be coming out at a faster rate? Is that why my plant is dead? No water? My lamp is a HPS 250 job. PLEASE ADVISE. Can't even get past the first hurdle! Rating: 5