advice to help prevent a cycle in a tank move

[Wayne]

Is the 180 going in the same place as the 75 was?

[skabooya]

before you start tearing anything out or disturbing anything too much suck out as much water as possible and store it to use in the next tank.
And yes either start with fresh sand or super clean yours. You can sell a few handfuls of your sand to others as Live sand to help seed a system. You can also put a small amount back in your tank to help seed or re seed your sandbed.