They are in 3.5 gallon buckets, I'm thinking that flowering time may be due to the roots, I pretty much followed the same feeding schedule as you. They were able to get some huge roots due to the hempy grow medium I suspect. It's by far my favorite so far (this is my fourth grow total). I'll post some pictures later, they are starting to fill in quite nicely!!!
Oh, sorry if you're quote doesn't show up, I'm on mobile and done have the app.