My first ever grow - Cheese or .....

It looks like a few possible issues her roots are a bit wet or she is in a state of transplant shock from going from soil to coco or your lights are too close .The red stems and pale color leaves are a sign of nitrogen deficiency possibly others. She just isn't taking enough up through her roots. I don't see any perlite in your mix. you need to have about 25-30% perlite in your mix to allow for a free draining mix. Also you should lower your ph to 5.8-6.3 they are better able to absorb nutrients at that ph range. I would also raise the light up slightly to eliminate the possibility of light stress the indication is the canoe shape of the upper leaves. I would let her dry out a little bit before your next watering you don't need to water the entire pot her roots are still small. maybe an area about 6" around the plant. I would also suggest that you may need to increase your nutes a little bit raise it slowly go by your brands feeding schedule which should be available on their web site to give you a better idea. She should green up after she gets more nitrogen. Good luck hope this helps I'll follow along.

After the switch to 12/12, the plant enter a stage of rapid growth, know as the stretch or preflower. Depending on the strain the first signs of buds will appear during the 3d or 4th week of flowering, some fast strains will have the first sign of buds at the end of the 2nd week of flower. As for your other question, get an EC/PPM meter, it takes the guesswork out of feeding.

Hi mate looks to me that you may have a sativa dominant hybrid strain ( flower development and leaf shape) Your buds don't look too bad Lots of visible trichomes and generally fairly healthy. It's not unusual for buds to pack on most of their bulk during the final weeks of flowering. I would keep the HID's on 250w to keep the heat down you should be good 👍 hope I've helped 😀 and best of luck