Very impressive! I'm planning a similar structure. I have plenty of fiji, reef, and tonga dry rock; what was your process putting all the pieces together? Did you use zip ties, epoxy, glue, rods, pvc, etc? I really want to remove about 95% of all the sand and ALL of the rock from my 75gal and replace with a new rock structure somewhat similar to yours? You think me doing this will cause a huge cycle, making me have to temporarily remove the fish and corals? I just want a fresh start as the rock and sand is just littered with detritus despite me siphoning the sandbed often, using a baster to blow the low flow areas. And I have plenty of flow with a MP40, MP10, RW15, and WP25 all in my small 75gal