On the shed, I don't know if you've seen the inside from previous posts, but I have a cleaning station inside (tapping into the on-demand well for water), cabinetry and wired with lights and outlets. Hence, the "fish house" . And it is NOT staying, it is for sure going with me! And I built it as such that the porch roof can be removed and the shed itself is on skids of sorts so it can be lifted onto a flatbed. No way it's staying here!
The tubing is Bottomline 5/8" ID weighted tubing, and yep it's heavy! IIRC it's 1/2 lb per foot, 50 lb per 100'.
On the diffusers I'm sure glad mine didn't look like yours and luckily mine cleaned up without any scraping. Of my 4, 3 of them are shallow which is why the disks are closer together, which appears to just be a matter of the length of PVC between them. I'm selling the system so if someone needs deep diffusers I'm guessing I could just lengthen the PVC on the shallow ones.
CC, it's beyond beautiful out here and I'm truly blessed to have had nearly 5 years to be here, learn what I've learned from the great folks on this forum (with the privilege of meeting several), and done what I've done. It was a new chapter when I moved here and it will be a new chapter when I leave. Yet someday I will again have a pond, one I can call my own!