Newbie Needs Help (yellow leaves)

Okay...first grow newb here.

I am growing skunk I picked up from Amsterdam Seeds.

Growing in soil Fox Farms Forest Mix... it was perfect PH when I started.
For the first week it was looking good. Fast growing. Nice and healthy.

Then... I had to leave town for a week. Left watering to a friend. Three days later... I just received phone call saying that leaves were turning yellow and some wilting.

The water is a solution of H20 with Grow Big and a bit of Big Bloom. I am trying to follow the Fox Farm schedule (but a bit diluted from their suggestion). I premixed before I left.

The photos are attached. Can anyone give any advice?
I haven't had friend yet PH yet. I told him to just water with H20 not fertilizer solution till I figure it out. Oh ya... he is only watering once a day. The mix has very good drainage.

I had my friend take pictures and email them me. They are attached.

After reading this forum... I am guessing I have burned them with too much nutes. If so, what is the solution to that? Just keep watering them and let them recover?

Thanks in advance!