This is my first grow and I just recently noticed that the largest leaves on my new plant are curling upward like a taco, fortunately there is not any browning going on. We had a really gnarly heat wave for 3 days and I thought that may have had a lot to do with it. The plant was also getting a little close to the light so I started with LST and dropped it down to roughly 3" away from the light. I had started the plant on 1/4 strength Flora-gro + Flora-micro (no flora-bloom) with a PH of 6.0 (side note. should I be testing the PH of the water before or after I mix the nutrients?) Once I saw the curling I switched back to straight PH 6.0 water. If the problem gets fixed will the leaves return to normal or are they permanently curled and damaged? The other leaves seemed to have stopped curling over the last couple of days which makes me somewhat relieved. I have read it could be a MG deficiency, too much water (which I doubt) or too little water. Too many paths to choose from and I would like to fix this before it gets out of hand. Can anyone point me in the right direction? Sorry for over explaining. Below I have more details and a couple of pictures to hopefully aid in solving my problem. Thank you for your time. - Hydrofarm jump start. Light 3"-4" away - Medium is rock wool - indoor temp is roughly 78 degrees - watering with 6.0 PH once per day (aside from the 3 days of 1/4 strength nutes) as long as the medium feels dry to the touch. - light cycle was 24hrs up until 4 days ago and it's now 18-6.
Test PH after nutrients.... PH should be closer to 5.8 if possible. 5.8 seems to be a sweet spot, although varying that later on in the cycle can be something you look into. You need to move those things to a bigger medium, that rockwool won't support much larger of a plant. It kind of look slike a PH problem. How are you testing PH?
Thanks Ohspyro. I'm testing with the Milwaukee PH600 and using the General Hydroponics PH kit. I'll def try getting the PH to 5.8. I have bigger rockwool squares that I am transferring them into later this week and into a drip system.