I helped a buddy of mine move his 45-gallon a few months back, and we had no fatalities. Here's the play-by-play, pretty much, of how we went about it. You're probably going to have to think bigger being that you have a much larger tank, but hey, anything helps lol.
1. Took out all the rocks that didn't have corals on them and put them in a spare 20-gallon long tank, then poured tank water from some buckets and filled the tank about halfway. The tank was across the back seat of his car, and we just brought the rocks and buckets with water outside, since there was no way we would have been able to carry it.
2. Took out the rocks that had corals on them and placed them in buckets of tank water, carried these outside and put them on floor of the car in the back. Be careful not to crush any corals!
3. Siphoned most of the water out into those 5-gallon Culligan water jugs.
4. Netted the fish and put them in a 5-gallon Culligan jug so there was no chance of escape. We only filled this one about halfway to make sure there was enough oxygen. Siphoned the rest of the water, left about an inch of water above the live sand.
5. Put the crabs in one fish store bag, snails in another, and starfish in yet another.
6. Transferred the tank and stand to the new house and added all the empty water jugs. Immediately ran filter and heater while we added the live rock and water from the 20-gallon long. Since we couldn't lift the 20-long, we had to carry the rocks inside to the tank and siphon the water into buckets and dump them into the tank.
7. Floated the bags of inverts while we added the coral rocks.
8. Added fish and inverts, then put the hood on, lights off. The water level was a little low so we mixed up a fresh batch of saltwater and added it. [Definitely have a few gallons ready prior to the move instead of doing it last-minute like we did.]
9. We waited until the next day when the tank had cleared up to do the aquascaping.
We had no fatalities, however, I woudn't suggest just dumping the fish and inverts back in like my friend wanted us to. Sure it was the same tank water, but the temp had changed a little. I probably would have bagged all the fish individually and floated them to regulate the temp, but that would have taken more people than we had. Also, I'd definitely run some carbon once you get it set up again to help clear the tank up faster.
FYI--I scooped up all the inverts with my hands up place them in bags, but my friend had a lobster that I was afraid to pick up. He scooped it up with a net and while trying to get it out of the net, my other friend ripped off one of its claws. It lived, but just a lesson, don't net stuff that has claws. If you're afraid to touch it, scoop it up with a cup lol.
Hope this helps!! Also, maybe you should list your tank inhabitants and equipment? People might be able to give you better pointers based on that.
PS. Where do you live? Maybe some people from this board could help you out. You never know! :joy: