(Double Grape x Skywalker) bx Skywalker

It's sounds like slight nitrogen toxicity, from your explation. Crispy leafs are early signs of leaf degradation. Still in early stages.Did it start of light green, then go that color brown color then turn to crispy dead parts. Because it's only part. I see your using coco so the light green before turned to crispy brown means slight tox. Or if it happened fast it could be a major problem to come up. Looks like early stages and looking through your diary. Here's my diary on heavy N tox but the fix is the same. Flush with distilled PH water at 6.2 max and then feed same watee for 2 days and start restart ur nute programme slowly. Try avoid N nutes or lower their dose and give nutes sep for a few days instead of doing a mix fixed my lockout on my zkittlez hydro. Happy growing friend. Check new growth them leafs will not heal. As you know that I'd say. Good luck mes if any more questioms about sign of N/salt build up thst causes nute lock out or build up of a N. Happy growing friend