This is only my opinion i see you have red stems so i would say its a nute problem
Greenthing Reviewed by Greenthing on . Two questsions. Ok, I have two plants I'm currently growing. One of them just had a pH issue that continues to show up everytime I grow (I have no effin clue how it happens but everytime my soil goes RIDICULOUSLY basic/alkaline) but I flushed that issue away. The other has been a weak / problem plant since day one but it seems as if it refuses to die so I figure I'll keep it around for growing experience if nothing else. First plant: It's the much healthier looking one (obvious given the text above) but i Rating: 5