Athos answered grow question 2 weeks ago
I took a look at the earlier weeks of the whole diary. I think the whole lot of them are growing really slow, you even chopped 2 of them for the same reason. And the only reason I see that cause that is low temperature; you've been having 20°C to 22°C (68F to 72F) during the day, which is kind of low, and you don't even mention lights out temperatures, so I assume they are even lower. Keeping the temperature above 23°C (73F) and below 26°C(79F) will speed up your rate of growth dramatically.