Hi , I just got 2 more in mail today. I like them and I use the 1.8 head on mine even on my 1000 twist.Set it around 4.0. My
juice turns dark too.I thought it was cause I use sweetener and add my own so it's pretty sweet Don't let it bother me Just clean it more . Also if you have some leaking I found out when I unscrewed the top it was turning the head and was making it lose .So I just make sure when I fill it or when I put the top on that you tighten the head real good.
I do like the vape I get from the ccT2 and it's a easy draw with big cloud. Anyway with the 2 new one ,I now have 5 and 10 heads (which are great to clean) aftwr I clean the head I air dry it .Works like new when I use it again Hope this helps.