Way too much water.
Your first picture looks so overwatered mate.
I can even see water hanging from the lightbulbs (not a good idea, the bulbs can explode if they heat up with moisture on them).
It's not a bad idea to let your soil dry out sometimes, resembles nature a lot more and your plants learn to grow with the environment a lot better.
Also, don't mist the leaves too much, if you have to, mist the inside of the leaves.
Water hanging on the leaves combined with some powerful lights = burnt leaves.