leafs tips are burnt (see pics)

[dandanbo]

Hi
my plant is about 5 weeks old outdoor grow I notice that some of the old leafs tips are burnt (see pics)
PH is 7 (not accurate)
I start to give it BIO Grow 1 cc for a liter last week
:: BioBizz-BIO Grow (http://www.biobizz.nl/products.php?nid=190&cat=p)

any Ideas
Thanks

[robwalker]

If u can arrange your plant(s) away from too much sun, otherwise they'll def get zapped

[growingweedoutside]

If u can arrange your plant(s) away from too much sun, otherwise they'll def get zapped

Agreed with you