Hey partner, I have been out of the loop for a minute, but am slowly getting back into the office to check everything out. With the bloom, I would just wait until the last few or couple weeks and then drop your normal PPM in half and use the bloom nute and if there is no sign of burn you may bump the normal nutes back up a little. I wouldn't wean them down because when you hit them with the bloom nute I think that it will be kind of a shock for them to have been weaned off of a high dose for a week or so and then jump back up so quick.
Glad that the PVC piping worked out. I have about 9 different strains going right now and they are mostly local and have different growth patterns so I will probably have to pull out every trick in the book to maintain them the way I want, nice and big.
Well, keep up the good work.
Adieu