Super skunk DIY Cree Led Grow

Hi everybody i've assembled a cree cbx 3070 and i'm vegging a SS. I'll add another cree led on flowering stage.
I've some problems with some leaf can u give me some advice?

Seed: Sensi Seeds Super Skunk
Soil: Bio Bizz Light Mix
Humidifier: Pro Mist 4
Box: 50 x 100 x 150
Nutes: Advanced Nutrients Organic Iguana Grow

Hard to tell with the lights on but I would check for this. The leaves look a little bronze though, is that from the light? If you are watering with tap water it could be a chlorine issue but not likely.
Potassium (K):
a.k.a. potash, this nutrient is key for the usage of carbs/sugars. This is key for sturdy/thick stems, small bushy plants and disease resistance. Its needed for all stages of plant growth, especially bud formation.

Deficiency: this has yellowing of leaves, from outside in, but with a dark green center vein, and curling of leaf tips, this is mistakenly diagnosed as nitrogen def or iron def a LOT. Stems and branches will be weak, easily broken. the plant may also stretch. *too much sodium (NA) can cause a potassium deficiency.