Nice looking grow Bud. Really like your plant selection.
We have gone to 50% coco, 50% #3 perlite and like Mofo we have found the ewc seem to make a very nice addition. I don't have a clue why, but we see it every time. We mix it in at transplant though...1/2 cubic ft per 9 cubic ft of the coco/perlite. Top dressing at flower would probably be a most excellent idea also.
One thing I might suggest would be vegging in smaller containers or sizing up when you transplant. We find a shitload of root growth takes place during stretch. If your roots are banging against the side of the container or circling it seriously limits your growth potential.
We also like to pinch every branch at the beginning of flower. It seems to help them stack flowers better rather than string them out. You have to be careful though...when we aggressively pruned to form big colas we ran into a little bud rot problem from them being to big/dense. I think it is a tradeoff you make to go vertical and over a pound a plant.
Also be careful about pruning to an open center too early. It puts a lot of pressure on the branches.
Anyways...very nice looking grow.
Lots to like in this post; he's going with 50/50 coco and perlite, Dank's 'hater buckets' are even more hydroton and less coco, seems to be a good direction.
EWC= earthworm castings, and I think these are extremely valuable in coco and other substrate style grows, organic or not, because of the mix of available nutrients, microbes and the fact that EWC has a lot of enzymes that help other processes along. This kind of activity in the substrate is why I've decided to step away from RDWC for awhile.
An excellent point about finding ways to encourage root growth headed into flow. The truth is that MMJ as an annual in the wild spends much if not most of its time in flower. It therefore stands to reason that the plant would grow aggressively in the beginning of the flowering cycle, to ensure it gets everything it needs later on. Dank's ez rooter aeration frame find is definitely the way to go if you can afford it. I'm running at least my first batch in 5 gallon buckets and I AM concerned about root circling.
I hadn't heard the tip about pinching every every branch at the beginning of flower, but this too makes sense. Getting too lanky a plant interferes with its neighbors and hard to hold up, while reducing yield density. Indoors, that means less yield overall. I used to make the last topping right around the beginning of flower and it worked out pretty well. This may be why.
Overpruning is never a good idea, unless the aim is to intentionally stunt/bonsai the plant! Since we're generally not trying to do that, this is also good advice. Better to trim selectively and be more consistent with it over the first 2-4 weeks. See Desertsquirrel's comments on topping and training.