Helpppp!!!!! Pleasseeee

I need Help.... take a look at the pics and tell me what you think!!!

Ebb and flow system... the H20 has been on for 15 minutes every 3 hours...
the Nute PPM is 420 the ph is between 5-6 way closer to 6.. lights are 24 hours

heres the pics.. thank you!!

They look good to me..

delstele said:

They look good to me..

Click to expand...

looks like overwatering. try waiting till your rockwool cubes feel dry to the touch before starting the next watering cycle,and keep track of the time it took for them to dry out, that should be your watering schedule. even though the rockwool feels dry theres still moisture inside.