Rust spots, whats the... Root cause? Pun intended.

I guess I didn't specify best enough, I dont know if my soil is "hot" because after testing ph run off of just my soil with water that is around 6.4-6.6 ph and it test about 6.3-6.4 ph. Plus testing my run off yesterday with a flush I did with the same tested water of 6.4-6.6 ph resulted in run off at 6.4 ph in my actual current grow medium. I can flush again but it seems as if my plant is in decent range for ph. As for fertilizer and nutes, I only put such a small amount of fertilizer in the soil before I transplanted because I knew I'd be using other nutrients once I got them. Even with the fertilizer that was added about 2 weeks ago my soil is still testing in the 6.4 range so im not sure how to test further if its "hot" because other than the couple of tbl spoons of fertilizer I put in my soil I havent used any nutrients because I've been waiting for them in mail.

Cut off the blurple lights and take natural light photos or even with flash on..

Also may I add since I could only add so much to my question. I have tested my PH and my run off is sitting at 6.4, i put a small basic amount of 4-6-2 fertilizer and some 6-2-1 fertilizer at transplant into its 5 gal bucket to try and keep the nitrogen higher for the veg growth while I waited for my nutes in mail. My soil is black gold organics and all natural or whatever its called I forget off the top of my head. My guess is some Cal-Mag might help but this is my first grow and im no expert i figured I could get some opinions from more experienced people. Let me know what you guys think I just wanna fix it before it really becomes a problem. I head its a very resistant plant but I dont want to stress her out any more than she needs you know?