K deficiency?

Wow, you really have so many things going on here - Autos, photo fems, fast versions, little plants, seedlings, 24 hour light cycles, big electronic devices (humidifier? ozone generator? inside your tent), I really don't know where to start. Leaf damage looks like heat damage, not potassium deficiency. My advice would be to decide what you are trying to achieve here. As this is also your first grow, I believe you have bitten off more than you can chew. There is a great article in the Grow Diaries "Blog" about growing Autos that might give you some ideas. Growing autos and photoperiod dependant plants in the same tent is going to raise its own issues and I would recommend either choosing which you prefer to grow, or having two tents that can grow these vastly different types of plants independently. There are so many different requirements between autos and photos that I believe you are making things too complicated for yourself. Far better to get a general understanding of what is required with cannabis cultivation, than trying to do too much all at once. I wish you all the best luck with your "empire building". Ever heard of the "K.I.S.S." principle? I really hope this advice helps..... Organoman.

What unit do you have the plants near? Is it putting off heat? Looks like it's the ones near that unit.

I think some of the aur from the aur conditioner might find its way to that plant..