On both of my GBs, I originally started with the Bell Siphon in the middle of each bed. Found out that it was harder to dig out and keep the media from floating back in on all sides. I abandon those because of the 1" drain pipe, and tried a more direct approach with a 2" drain pipe. The corner is easier to dig out and control the floating media.

You could use the same kind of media block that the Bell Siphon uses and not bury them. My thought is when the PVC barrier on the Bell Siphons gets root bond you'll still need to pull it out to clean it from the outside. About the same amount of work the pull and clean either one, but with the Pipe Siphon having two media barriers and using larger diameter pipe with no restrictors it should go 2 - 3 times longer before it needs to be cleaned (much less work over time).

I was planning boxing off that corner for easier maintenance but since it was operating so well I decided to bury both of them. Maybe plant something that doesn't root too deep or just not plant there at all.

On my 1st drain system in the middle of both GBs, I just remove the bell and lengthen the stand pipe...they are now used as my emergency over flow.