Late stage burning leafs

Hello everyone,

I have a problem with my plants and the problem came over night just suddenly. I searched all your site and other sites, and dont know what is probelm.

Growing under 400w and the temeperature is 24C-26C, humidity 55%.

I was wondering maybe the cause its the fertilizer. Coz i mix 2 fertilizers. 1 liquid for flower with NPK 6-8-8 and 1 crystal with NPK 13-40-13.

Here are the pics of the plants who got burned

Burned really bad. I would flush your medium immediately and back off the feed. No reason to add that 13-40-13.

"...Coz i mix 2 fertilizers...."

muahhh-ha-ha-ha.........this.....will be.......my greatest plant EVERRRRRR!!!!! ahhhhh-haaa-haahaaa

*lightning and thunder*