Mosquitofish (I have them in my 75 gallon reef just fine)
Tank Size 20 Gallon for adults, at least 10 for juveniles Temperature Mosquitofish are commonly kept in ponds, so a temperature of 60-85 would be acceptable Adult Size About 3", the biggest I've had is about 2.5" Temperament Peaceful, generally stays away from the other fish Reef Compatible Yes, they generally stay away from the other fish, and invertebrates. They do not interact with corals in my experience.Diet In my experience they eat anything that their tankmates will eat: mysis, flakes, pellets, and pretty much anything else. Origin Mississippi River, down to the gulf, and also found in Northern Mexico. They are found in full FW, all the way up to full SW (I got mine to SW through drip acclimating for 8 hours)
I'm going to have to disagree with the Chromis being a good starter fish. They are a schooling fish, but in the aquarium are hit and miss with picking each other off and as of late are shipping with more than their fair share of disease. Also, on firefish they are relatively easy to care for, but are super skittish (hide a lot) and are likely to be the number one target for bullying by even Peaceful fish trying to assert dominance.
Among my favorite Beginner fish
Melanurus Wrasse (and other H variety wrasses)
Pajama Cardinalfish (imho more durable and colorful than the Benghai)