I have 2 established planted 20G High tanks community tanks, and I am thinking combining both in a new 55G. The larger aquarium would give the fish more room to swim, and I would only have to maintain one aquarium instead of two. Both aquariums are stocked with similar peaceful community fish. I plan on transferring the substrate, plants, and décor from the 20 gallons into the 55. This would at least transfer beneficial bacteria from the cycled tanks to the new sterile one. Would anyone have any advise on how to do this safely without harming the fish, or point me to the direction of some websites or YouTube videos? Particularly, is it safer to transfer one, let the 55 cycle, and then transfer the second, or could I do both safely at the sometime.