faux sandbed vs bulkhead
 

any ideas on how to do my faux sandbed without permently sealing in my bulkheads, i would rather have the faux sandbed right on the glass instead of the starboard or plexi idea... and ideas on how i could lay it without sealing in my bulkheads??

You could create an acrylic box/cover that covers the bulkhead just barely, and has a hole in it for you pvc obviously.

You could silicone in the acrylic and then cover it with the same faux sandbed. You would not have easy access to the bulkheads, but could get to them if need be, and they would not be all gummed up with the faux sandbed mix.