Hi 'Dee- Looks like two unrelated things, both spotted by the others,... the leaf is looking cooked, causing the curling, and crisping, so keep the lights several inches away, even at that wattage,...*** I do see the early signs of Ca-Mg defc., so treat as recommended with epsom and molasses, or with a dedicated supp',.... (epsom for soil treatment: 1 level tsp/quart, or foliar @ 1tsp/gal..... molasses is great for the soil herd and plant too (it has Ca, Mg and some K as well as the sugars): 1T per 1/2gal soil drench, half that for foliar....Treat a couple times over a few days or so, to watch for reaction, then go from there. BTW, for future ref', foliar is the fastest way to get stuff into the plant, BUT it's very important to use a water spreader when doing so,... it's all about surface area coverage! Spreaders/wetting agents take the surface tension out of the water, making it coat more evenly over the leaf surface, instead of beading up; basically, more SA covered=more absorbed! Spray top and bottom too, during lights on BUT not placed back into direct light; pull them aside for a while, allow them to dry more slowly and not potentially get light-burned; they should be fully dry by lights-out to avoid possible mold issues,....:smoke:
*** (just saw this above at top)*** Don't yank them mate, they're nowhere near that stage of messep up! As mentioned, soil will take longer to treat than will foliar, but you symptoms are mild/early, not severe at all, so be patient! Foliar is something I like also because it bypasses the soil and roots, just in case there's an issue there,.... (not looking like it in your case)....
dont let this go out of controll guys.. stay on topic and keep the vibe 
