Betta Fish: King George is moving

This is George and I love him. I had a nano tank (2.7gal) set up that I was intending to put a max of five cherry shrimp and a bunch of plants in. When I went to get the shrimp, George looked me directly in the eyes and I couldn’t leave him, so now I have George and Gary (mystery snail you can see behind George) who was only the size of a nickel originally and also a banana plant for George. George and Gary started growing rapidly and I knew they needed a bigger tank ASAP. I have successfully cycled a 20gal long planted tank, but I’m still really terrified to move them. The only major difference between the tanks is the nano has ph 7.2 and the 20gal is 7.8-8.0. I have no idea why the nano tank is more acidic. The big tank has driftwood leaching tannins. I know I have to move him, but I’m scared 😭