Gelato OG Clone

Hello So it's looking like a couple possibilities to me. Is it being over watered at all or slow drying soil? High temperatures and then possibly root stresses, maybe root bound. If you look at bottom of the cup is it fairly full of visible roots? If so maybe go for a transplant. You can also use a kelp extract to help make stronger more resilient plants and helps to build healthy plants and roots. Happy growing.