Hey crisc,
How are they growing with 6 to 9 hours a day of watering? If they look ok, keep feeding them plain pH'd water, check the pH at least every other day and give them water as they need it.
If they aren't doing well and it looks like they are overwatered, then back off the feeding time to half an hour each watering. If that doesn't work, back it off further to 15 minutes each watereing.
Keep your pH between 5.5 and 5.8. In a few weeks start nutrients when they tell you.
good luck once again.