Guys, what is your opinion, what did I wrong?
Too mutch food? The soil is from regular garden shop.
Too mutch light or wrong PH.
Maybe some nutrient missing?
Looks like the epsom salt cause nutrient lockout. I would flush your soil with plain ph water to get all the salt out of the roots. And after the flowering stretch is over they dont need much nitrogen. This is what causes the burned tips the leaves to claw down on the ends.
Do you give the plants a break from nutrients? For example feed, feed, water, feed, feed, water etc. If not it is strongly advised. Already check your pH is around 6 to 6.5 no higher. And flush out any excess salts once a month or so.