I did a transfer from my 55 to my now 120 about 2 months ago. I put everything it big storage containers during the transfer: fish in one, coral in another, rock in others. I didn't reuse the sand because you have to worry about the diatoms and all the different unwanted critters now living in the sand like bristle worms. I drained all the water from my tank into my containers, already had fresh saltwater made as well as plain fresh rodi water. I kept heaters in the fish and coral containers as well as airstones so the water would be agitated and everything was getting oxygen. I used all new live sand, added all of my rocks (that's didn't have corals attached, before adding water), added some new rocks too. Then i added the water from my old tank from the rock container, and started filling with fresh saltwater too. Once tank temp was right i added my corals and more tank water. Then once tank was filled I drip acclimated my fish and added them. I also supplement bacteria with Brightwell Acquatics Naturbacter7 to help add bacteria. I use a 40 gallon sump on my system and it's perfect. 20 gallons is way too small. Everything today has been thriving incredibly!

since don't have anything to drill glass.

