oh ok then that will probably be fine then def leave out the firemouth and then just see if you can get pairs of each of the dwarves you listed to get along, should be possible in that tank just make sure youv got lots of driftwood and stuff to separate territories, im not sure how big the puffers get or their temperaments so cant comment on that but aren't "freshwater" puffers usually brackish? is there any puffer that is actually totally freshwater for its whole life?