Could be nute burn with dead leaf tips. I don't see any brown spots of the rest of the leaf/leaves. Can you talk about your soil and what you're adding nute wise?
Soil Pro-mix HP with castings, dolomite and seaweed meal
Ph -feed 6.5. Soil ph is good, put a 1:5 ratio of soil to water @ a ph of 7 and the ph after an hour was 6.8.
Nutes - GH floranova grow, rhizotonic, GH rapid start.
- Gave them 1st feed of Flora Nova after 2 weeks with just Rhizo and Rapid start @ ppm of 450. This was too much and had to scale back to 300ppm (first time with Floranova). Since then all the new growth has shown no signs of overfertalizing. One plant showed some salt lockout that was cured with a flush which was surprising after only a couple of feeds with nutrients. I am pretty sure I added to much seaweed meal, first time using it and the plants showed signs of high nitrogen and leaf claw before I had fed any nutrients, so this could potentially be linked to the seaweed meal. But I should add that I have some younger plants in coco that had no seaweed meal that are showing the start of the same symptoms. i don't have a RO filter but I do have an airstone in my reservoir.
So I'm unsure and curious to get to the bottom of this. I'm going to add some Cal/mag to the next feeding and see what happens.
Any input is appreciated!
Thanks