I would say the epsom salt droped the PH way too low so when you watered it the plant couldn't uptake the nutes. whan you get your kit do a test with the same amount of epsom salt and water and see what you get.
They give you the basics and makes for a good ref. I think i have videos to some of those books, and more that really get in to the science of cannabis. Happy growing.
It looks like nuts burn. Might cut nutes to 1/4 and check the ppm and PH of your runoff next time you water. coco by its self can be very touche, at least it was for me. There are people on here that like it and could help dial it in better.
Its most likely N diff. but have to see when you get other pic uploaded.
Till then you can look at these and match yours up with the pic.
http://www.growweedeasy.com/cannabis-symptoms-pictures
More will die from the lights and heat as ladybugs cant take the heat cannabis can. And the soap kills the mites by forming a air bubble on them and they suffocate, so unless he is spraying the ladybugs themselves he's ok.
I use dawn, they have it. I have organic soil so i stay away from anti-bacterial, dont want to kill the good stuff but i have never heard anything bad happening when others use it. Lots of luck and happy growing.
3 drops dish soap and water in a spray bottle will kill the mites on the underside of the leafs and it wont kill ladybugs. Water your soil with dish soap and water for gnat control in the soil. It wont kill all gnats in the soil but will knock them down so your ladybugs can eat the rest. This...
it looks like N diff. but if you just gave it nutes then you already fixed the problem. looking ok for a first grow to me. Have you been PHing the water?