American Pie

Your plant(s) seem to be doing fine , the stem takes a bit of time to thicken up at first and get strong , I might suggest using a silica product this will aid in boosting the stems strength . For the time being your doing well with some LST over time the stalks will fatten up naturally or like I said you can get some silica and add it to your nutrient water mix up . You could also increase the amount of wind your plant faces for addition stem training this will also fatten them up and make them sturdier . If your going to use a silica product I would consider rhino skin from Advanced nutrients . Really cost effective and its a really great product that you can use from the start to finish . I will say though that your going to need an extra hour or so of mixing time when you make your nutrient batch for your plants , I say this because silica takes time to fully dissolve in water so that your plant(s) can absorb it . I hope this information is helpful to you on your quest for glory ! Happy Growing!

Your new twisted leaves are not an excess/ def issue neither a disease, I guess it is just the leaves that are trying to be on the best position to take all the light so as you have practiced LST the leaves are trying to take the best position. Your issue is not PH related and you'd better know that cannabis can grow in soil with a ph range between 6 to 7 without any harm done to your plant, moreover the soil have a self buffering propriety so the ph is tending to "auto stabilised". You can check the ph and composition of your tap water on your local company website to know at least that value