Leaf burn? Dead

That looks like moisture issues. Pull those leaves off so the plant doesn’t waste any more energy and just be careful when watering. Not too much and don’t splash the plant! Good luck ✌️🏻💚🌿💨

Hi there , when growing in an organic medium like happy frog on top of black kow you have plenty of organic matter in the medium to feed the plants for at least 30 - 40 days from seed or transplant. I happen to be an organic grower myself that uses only organic dried amendments. After the 30th or 40th day I will re amend my cocoa with a top dress of some high-quality time released organic fertilizers that are rich in seabird guano, kelp meal, and some other organic material. Just like the stuff that's in happy frog. I just build mine from organic coco. I like to keep my medium ( soil or coco ) at a pH between 6.0 and 6.8. I notice some deficiencies start to pop up when the pH of my medium gets out of that range. 6.5 is the sweet spot. I don't use gen hydro so can't help with that part. I use organic dry amendments for veg and flower on all my cannabis grows. But hope this somewhat answer / comment helps! ☺️