concrete is hydroponic, i think im using the right word here. when i used to build fences for a living we would put the crete in the hole and then soak the hole with water, let set and come back and do it again before we started building. within 48 hrs you couldnt break it with a sledge. just my 2 cents worth.
Its all about how ya wiggle it!
I just filled the bottom with a few inches of water then put my bamboo in and then poured the bag of quickrite in on top of it and filled the rest of the bucket with water. I didnt do any mixin or measuring that quickrite is pretty much idiot proof. Dont sweat it . I left them overnight and dropped them the next day and they were fine