So far so good! The transition from a cup to the 3-gal planter was simple and low stress. I modified an idea another grower posted online. Using the two cup method described earlier, I placed the entire setup into the 3-gal planter to provide a hole exactly the same size as current media the plant is in. You can still see the original peat plug if you look closely. I was also able to shift to adding nutrients at half-doses into the cup so the surrounding media was the exact same solution when the transfer took place. A big shoutout to the folks over at Coco for Cannabis for the large amount of information and tutorials on getting started with my fertigation setup. Still trying to figure out the EC thing, but it has been pretty low maintenance way to go so far!