Wedding Cake mainline (Norcal Farms)

This week I was waiting for 2 of the plants to recover from their burn. I think the problem was a few things compounding. I transplanted to bigger pots a couple weeks ago and got more soil from the hydro store. I got coco and asked if I could add it to my soil grow or if I should get more soil. He said it was fine but now I'm reading that soil and coco have different pH. Since the 2 that got burned were the 2 that were transplanted into 7 gallon pots while the 5 gallons were fine, that indicates that the medium may have something to do with it. I also kept my 1000w light down to 75% for most of the week because I felt like it was too much for the hurt plants. The hurt ones are right under the lights too. They're looking much better this week and all the new growth is mostly ok but the tips are still coming in a little twisted so I'm going to flush with straight water as soon as they're ready and hold off on flowering.