I've had figure 8s, green spotted and even dwarf puffers, and they're great. Bumblebee gobies do well with them, and I also had mollies. Have some moss to float around and molly fry can hide from the puffs. Brackish is pretty fun to do, but some plants don't do too well in them, so it's something you have to play with what does and doesn't work. Makes me want to do brackish again!