Everyone's setups are different I have about 8 pea puffers with 1 Amazon puffers in a 40 breeder for almost a year now with No issues I had to take out about 5 albino Cory's because I seen there fins were getting nipped by the pea puffers now its been just the puffers together they don't mess with the big guy and the big guy doesn't really pay them no mind the big guy swims freely back and forth the pea puffers do nip at each other but nothing major just them establishing the pecking order they get along quite good and they are thriving my pea puffers are huge for pea puffers nice and healthy and my Amazon is nice and healthy his self so it's possible to keep them together but like I said in the beginning everyone's set up is different what works for me might not work for you just be sure to make caves with rock and wood with plenty of plants that's my advice
