Wow. Waretown. I spent many years hanging out in Waretown. You don't know a lady named Christine Importico by chance? Her son and I were close before he passed away. That is a small town. Do you still have to drive all the way through Lacey to get to the parkway?
Re the tank swap... I'm in the middle of that process, so this is my take on it.
Look at your parameters, how is your ammonia, nitrite and nitrate, etc? Chances are that once you start stirring up that sand, you will release some nasties. If you reuse any of it to jump start the biologicals, give it a rinse. If it is not too old, it may not be too gross. Otherwise, just save yourself the hassle and get a 40# back of Caribsea and call it good. I'm not reusing my sand. My nitrates are holding at 20, so I'm looking into live sand from Salty Bottom or Gulf Live Rock. Still holding out hope for TBS.
I will be doing the swap in stages.
Set up new tank, new sand...
I'll move the sump to the new tank and run a closed loop out of a rubbermaid on the old tank temporarily. The sump will be thoroughly cleaned before it goes on the new build. If I can afford it, I'll cut out the socks and replace with a fleece roller.
Fill with Synbiotic Salt by Tropic Marin - this has the biologicals in it already.
I'll run that a few days and test parameters.
If all is well, I'll move rock from the old tank (and any attached corals to the new and put some PVC pipes in the old for hiding places.
While this is happening, I will be putting any new or sensitive fish into a separate QT.
Once I am confident that all is stable in the new, I'll transfer fish, taking the least aggressive species first. The territorials will go last.
I think the most important thing is to keep your salinity balanced between the two tanks... as well as temp. Keep an eye on the parameters, as you may cycle.
I'm sure there are wiser folks on here than I am but in general, take it slow and move one step (or fin) at a time.
