How to- the big tank swap day

[jason604]

So it's about a week away till my new tank is rdy for the big swap. For ppl who done tank swaps before with lil to no losses, how do u guys do it? For past few weeks I've been slowly adding a cup or 2 of live sand from my existing tank to my new tank and a few small live rock at a time. I put all new sand in the new tank so far with rock that I bleached/acid bath n let cure in a bin for 2months. So on the big day should I take20-30% of my current tank water and swap it with my new tank n move all my corals n fishes into the tank all at once or should I move it slowly over a week or 2 span. I am capable of running 2 tanks at the same time. Old 75g full system will get sold once swap is done.