substrate

[Beverly]

The bottom glass ends up covered in coralline in awhile anyway. IMO, no reason to put starboard or anything else on the bottom. If starboard isn't completely sealed around the edges, crud gets under it, defeating the whole purpose of being able to siphon it out.

Also, don't worry about the look of a BB tank. You'll get used to it over time and you'll wonder how you ever had a sandbed trapping all that detritus all the years you've been reefing.