Hello Panta... I am a fellow soil grower and i would like to put my $.02
Most people have suggested you change your soil mix.. some people suggest you overwater... I will suggest your thinking too much...
Soil is one of the most easiest mediums to grow in because it already has its nutrients in it. Most manufacturers already are putting a good mix for your growing needs. When you add extra water (flush n crap) all your doing is wasting nutrients. Only add enough water to moisten the medium.
I have learned allot about growing marijuana from riu's faq but i must say...
if it wasnt for mandalas guides i think i would have killed a few crops... please do your self a favor and read there guides... troubleshooting guides...seedling care.. fertilizing...
i would start here bro..
Soil Guide