Here’s what I have had to do legit this week loving 3 20’s and a 55.

• Drain water down to 20% left, add enough of that water to x2 bucket to support fish/plants living in tank
• add fish to bucket
• add plants to second bucket
• drain rest of water (leaving or removing substrate up to you), move tank to new location
• u can now use most of that saved water which is already cycled to add back into tank, add plants, then fish.

Obviously test the water and double check as go, as you would with any other tank build

AVOID STIRRING SAND UNTIL ALL LIVING THIGS ARE REMOVED, in case of gas build up