nitrogen or pH problem or just aging?

1st grow, im in the end of week 5 flowering for my afghan kush and the leaves are increasingly more yellow, mostly fan leaves on the bottom that have died and i can just pick right off but most of the leaves on the plant have yellow tips and sag down.. i flushed last time i watered with 7-8 pH water since my runoff is always low (yellow with the pH drops) i just started molasses and just stopped giving it fox farms peace of mind fruit and flower and fox farms big bloom, trichomes are still more clear than cloudy but some parts have amber, what do you think?

Start using only water in the later period of flowering. If the pH is off then use what you've got to balance it. Use pure water with a nice pH to it and they will ripen as usual. Those leaves are going to yellow, that's great. It means that the buds will dry with a clean taste. More over it will keep yellowing as it would because it's a sufficient source for the plant buds to lurch nutrients from like the fat in your body will burn to feed other parts like muscles.

dude stabalize then ph in your soil next time with dolomite lime and use ph 6.0 water as it will drift up before next watering and all nutrients will be available,if you are using tap water leave it sit out for 2 nights before watering to let clorine escape from the water as chlorine will acidify the soil after a while,and is bad to your babies.
hope this helps aa bit for you

can i bring the pH up with spring water only or with molasses added as long as i test it to be well above 6?

i wouldnt be to worried man, could be the plant using the nitrogen in the leaves for further growth of the buds, yellowing of leaves is normal twards the end of flowering.

I would flush to lower the PH, then go from there. Soon enough you should be using water only anyway. Looking good.