PH problems

Hi,
I am new to the hydro...I recently purchased a mini cool cab with the LED lights...planted some seeds and they sprouted...BUT...they look terrible! Curled leaves, a bit of yellowing and no real growth...its been a week and a half since panting. I seem to have a problem stabilizing PH... I get it down to 5.8 but then 12 hours it is reading 7.0. Does anyonyone have any advice/tips? Thanks!

Do U have any pics?
You dont say what medium you are using. Rockwool by the sound of it? Rockwool is made from rocks which are naturally alkali and have a very high PH themselves. When using rockwool you should soak them in acidic water for a few days before using. Its very easy to drown your plants in rockwool also because it retains a lot of water. I start off my seeds in 1" rockwool cubes and use a syringe to feed them with plain water once a day for the first week or so, the cubes shouldnt be allowed to dry out though.
Your curling and yellowing could be caused either by having a high ph causing nute lock, but i think they are too young to have that problem, so its probably overfeeding and giving them nutes too young
Really cant tell until you provide a LOT more info though
HTH
Corkboy