Magnesium deficiency? Lower leaf tips dying.

Looks like they're hungry. Needing nitrogen. Are you feeding them anything?

If you checked the ph run off and it’s that low then your soil is too hot and needs some pebbles or coco added in the mix to cool it off. I use roots organics 707 mix and it has coco but not enough I always add an organic brick from Home Depot for 3 dollars and a few extra more cups of perlite. Good luck you’d be surprised how well they survive and become resilient.

They need a nitrogen boost and cal mag to balance out its missing intakes. Get coffee grounds and mix it with a cup of earthworm castings , put it on the top amend it in the soil and water with half the amount of what a gallon calls for each time you water every week instead of every two so I catches up. She’ll bounce back with her new growth and you could defoliate what died off early.

They are growing in soil (around 2/3 soil, 1/3 perlite). Watering with a ph of 6.5. I just checked the runoff ph and it is at 5.2.

It looks like potassium deficiency or your soil ph is out of range. Check run off ph. If in soil they like wet and dry times. So you gotta cycle a ph of 6.3 to 6.5 would be ideal. If in coco 5.8 is ideal. Ph and how much perlite in substrate or coco can effect a grow massively.

Lower leaf problems are there since week 1 (as seen in my other question). Yellowing leaves my guess is Magnesium deficiency. Just wanted to hear some professional opinions on this 😁