Even with your PH fluctuations, your plant really has grown vigorously in the past couple weeks. It really goes to show how resilient the plant is, and, how "forgiving" the cubes are. Like I talk about my the
"how veg time affects yield" it is amazing how the plant goes into overdrive at that stage. And I think you're right, you will probably benefit from some kind of trellis, especially if you think you are going to run out of height. Can you post a picture of your plant right before you put it into flower, and then another picture, 10 days before that?
>>>I chopped off the 2 lowest branches. They were very twiggy and never gonna go anywhere so....
AG's concerns are valid, however taking off a couple lower whimpy branches as you go to flower is fine; use them for clones if you want. Auxins are mostly in the upper tops, so topping will disturb auxins more than cutting off a few lowers.
>>>Also LST'd the 4 dominant branches to open the middle some.
LST is a broad term. Did you bend them a little or tie them down?
>>>I wanted to have a short lollipopping session
X-( You mean "prune" out some lower wimpy branches and fan leaves? That's fine, but erase this "lollipopping" term from your stoner dictionary! And no "sessions". Like AG was saying, we don't want to put the plant into "heal" mode or it WILL stunt growth. Removing a lower light starved branch here and there (over a 2-3 week period) is fine. But go sparingly, you will be surprised how much some of those will stretch. You can take a couple and tie them to the main stalk to point them straight up the middle of the plant if you want. There is no reason to take off lower fan leaves, unless they are touching the grow media. (someone feel free to enlighten me if you think differently) I always cringe when I see people pulling an edward scissorhands on their plant. Fan leaves provide energy for the plant, EVEN IF they are not getting light. And the lower fan leaves are not shading any bud sites. You know those stoner smurfs who made up the rule about soaking rockwool for 24 hours, also made up the theory that plants should have lower growth cut off, so they can get more "Air circulation".
If you've ever experienced root disease, you'll know the first sign of it: lower fan leaves turning yellow. This is the plant's survival strategy. It takes stored energy from the bottom of the plant and attempts to save the tops. Enough said!
>>>I am wanting to meddle as little as possible.
+1
About the PH. I like how you've opened up your range here. In the past I've grown monsters at 6.0, then calibrate my $hitty meter and realize it was WAY off and I had been growing at 6.6 with absolutely no issues. Some strains are more forgiving than others too.
About the PPM. Same here. I like your thoughts on this. Always better to error on the side of being too low. In cubes, irrigating twice a day, I would be no higher than 600, until you start to see significant pistil growth. <<notice I am thinking positively ;-)