hey guys, not sure what to make of this. lots of theories, pics and info included

So im into my first week of 12/12, switched from 600w mh to hps, carbon filtered, lots of ventilation soil grow. FFOF cut with potting mix (verm, permiculite, very light), 3 gallon smart pots. Changed on off schedule gradually before 12/12. Changed nutes a few days after starting 12/12. Been at a constant temp of 73-75 day and 65-67 night. Indica strain barney vanilla kush.I have a few theories about the diagnosis but alas, i am a novice grower. Got a separate veg room so im getting the hang of it. Just wanna catch this early. Noticing some oranging around the edges of some fan leaves and top leaves. The light is plenty high so i know thats not a problem. Just cleaned out the drainage system which admittedly needed it :/. Im not sure if this is heat stress, nute burn, a deficiency, or something microbial. Also notice the white area on one side of the smart pot. Mineral or nute buildup? Ive turned down my ballast to 75% while this gets sorted by my knowledgeable friends here. Otherwise, she seems thriving and healthy. I have some sledgehammer in case i need a flush. Throw me your wisdom guys!

P.S. - is the user's IP address masked auto or does it need to be manually. You understand how it is these days.

not an expert but looks like a little nute burn to me..

^^^^^ I agree

Thanks guys. That was my first thought. Probably a sledgehammer during the next watering

Also on the pot, it could be mineral or nute buildup, but it also could be mold/fungus. Mycelium from mycorrhizae (best case scenario) can grow through the sides of those smartpots from inside, I had that happen with me. As long as you are using Myco, and can be pretty sure thats what it is, it shouldn't be a problem, but if its not then you should be careful that you don't have a bad kind of mold potentially growing on the pot (like whatever may or may not be growing on that white board in the background), can you get a magnified photo of it?

Nutrient burn and build up.