First grow with some dis coloring help if you can, thank you

So I am growing 1 plant, the strain is moonwalker it is about a month and 2 weeks old in veg stage I'm using a 150 watt HPS light and bottled water but changing the ph to make it 7.0 and my plant has got some darkening on some of the leaves but not all? Can someone help with this and try to explain what is going on? Please and thank you

From the pics, and it's hard to tell from pics I would say it could be a Phosphorus deficiency. Another thought is that the leaves look really dry. I had similar looking leaves when I had a dehumidifier next to the plants. But honestly, it's probably a lot of things. HPS is not the preferred light for vegetative. You might be better off with inexpensive "day light" CFLs until they are a little stronger (check the box to make sure the light spectrum is around 5000 K) Also, 7.0 Ph seems to high even for soil. Lastly, they look really pale which probably means they are deficient of several different nutrients.
What are you feeding them? How often are you feeding? Are they in soil?
I'm no expert (as my rollitup stat sheet will clearly show), these are just my thoughts.

Thank you for replying but yeah I was going to get a 6000watt cfl because someone said that it would do better in vegetative stage and the hps in flowering I'm feeding the plant liquid karma and do you think I should drop ph to 6.5? They are in soil just from a shop locally its not any really good soil just lower grade. When I switch it to the 5 gallon I was going to get some better soil I feed the plant every 2.5 -3 days and the leaf does look pale but that was only on the ones that have that blackish color on them my other leaves are nice and dark green

6.5 is recommended for soil I think. I grow in coco and keep it around 5.5 For 1 plant I would go to home depot, get one of those reflective clip lights ($9), 3 bulb splitters ($3 each), and a pack of 60w day light cfl bulbs. With four bulbs you'll be rolling with 240w of cool light perfect for vegging, and you'll spend about $25. I'm probably not the best person to ask about soil but I've heard really good things about worm castings if you can get your hands on some.

Okay I am going out to buy those lights and reflector today, thank you for your help I appreciate it!

I think if it was Phosphorus it would have yellowed with brown spots and show some sort of N deficiency as well. But it could be Ph locking out and is still early stages. Try some dolomite lime, that will help bring Ph down and add Calcium and Mag. one tbl spoon per gallon of soil. At soil Ph of 7 you are on the line of Phos lockout. I keep mine at 6.8 fairly easy. Here is a link

http://www.thctalk.com/cannabis-forum/showthread.php?11726-Ph-Lockout-Chart

Where do I get dolomite lime? And thanks for the chart and help this is my first grow so I don't really know to much