need a lil advice-yellow edge and dead lower leaves

hi every one,
my plant is about 5 weeks old
growing indoors in a wooden big box-
hight 75cm
width 30cm
length 54cm
got 2 white CFL lights, each is-20W 6500K 160MA
temp is 26-28
didnt check humidity or PH.
i give it mineral bottled water
and for nutes i started to give- NPK 10+4+7

the plant looks like its fine but the lower leaves died and edges of higher leaves became yellow with weird spots
i added some pics of the problem and the general look
any one knows whats wrong and can give me some advice how to help my plant?

thanks

Hi
I was also giving my plants mineral water and nutrients. The water started off at PH 7 ( it says it on the bottle) however when I added the nutrients it drove the PH to over 8. I didnâ??t have a digital PH reader until my plants really started to develop all sorts of issues.
Most of these issues where quickly resolved after I purchased a digital PH meter. Now Iâ??m sure my plants are getting their feed at the correct PH and the run off can also be checked.

Itâ??s a fundamental to get the PH correct, so I found out the hard way

i was reading on a thread yesterday, that when you use distilled h20 you need to supplement calcium and magnesium, wonder if its the same with mineral water. or it could be nute burn. also at 8.0 alot of nutrients are lock out, i say get the ph straight and you should be good. you may have to wait till u see new growth till you see if you get it straight

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I have a couple outdoor females about 4 ft. and the new growth is really yellow, the rest of the plant is health and a nice green. Also some of my lower leaves are yellowing but not sure if its because I reduced nitrogen due to flowering. If any one has advice or have had the same issues please let me know asap.