plant needs urgent help :(

Ok so I have this plant thats just starting its 5th week of flowering. Its my first grow and only bagseed and the pot its in I think is like a 2 gallon pot. The plant started giving me trouble around the 15th (almost 4 weeks into flowering).

Its currently under a 250w HPS with a couple CFLs on the sides.
Here is the watering schedule since a week prior to the problems starting:
4/4 - .5 gal 20-20-20
4/6 - .4 gal water
4/8 - .3 gal water
4/9 - .25 gal 15-30-15
4/11 - .3 gal water
4/12 - .5 gal 15-30-15
4/14 - .3 gal water
4/16 - .5 gal water
4/19 - .5 gal 15-30-15
4/21 - .5 gal water
4/23 - .4 gal water
The plant food Im using is generic Jacks Classic or something of that nature. I think I made the mistake making the nutrient solution too strong and giving it too frequently because I did increase the amount a little.

Heres what it looked like on the 15th:





I was away for the weekend and so I didnt give it any water since Friday, and the last time it got nutrients was on the 19th. Came back and its gotten worse, and theres now white blotching on one leaf that is mutated and I cant find anything that talks about these symptoms.





I started giving it water that had a pH below 6.2 because the runoff was still above 7. The last time I watered it, the runoff was just under 7.
I have a grow journal here if it helps to see the progress.

What can/should I do Thanks.

Believe its a PH problem, Nutes getting locked out

Get a Soil tester, to test your Soil.

Will do thanks. Giving it such low pH water was not probably the best idea

damn, beat me to it, a proper ph is very important. if its not in the right range it causes lockout and all feeding does is make it worse even though your problem may look like a def.(which it is technically i suppose) but your problem is really ph. flush with properly ph'd water and make sure you ph your water from now on.