boldtogether,
The 12 feet of tubing was easy enough. It is the default length that Home Depot sold. It was the 5/8 variety, which is what the Eheim 2228 uses, natively. It was a pain stuffing that Efisubstrat (not the "Pro", but, the original) into it -- only to replace the Efisubstrat with deNitrate a week later!!! The hose was not heavy at all.
It was working beautifully until it clogged. In the height of +90 degree summer temperatures, and, without air-conditioning, I just no longer have what it takes to see this through. I have no doubt that, with some minor adjustments, I could have made this work, but, that is now irrelevant.
Overall, I think the concept was good, but, my implementation would require several rounds of fine-tuning. I should have started this experiment in October!!!
I don't know if you are just joshing with me or what, but if you are actually complimenting me, then thanks. It is appreciated.