I have just moved my 4" mac and 3.5" rhom into a 180 us gal tank sectioned off across the middle. I used an old plastic ice cream container 10"x6"x8". Cornered them, they just swam in, then put the lid on. Floated the container to acclimatise, let them out, they didn't even know they had been moved. By the way, they were in separate tanks before I moved them. No signs of stress, and I still have complete nets!