[Ebook] The New Guide to Aquarium Fish – Miscellaneous Freshwater Fishes – The Halfbeaks
The halfbeaks occur in southeast Asia and are found in both fresh and brackish environments. Most of those available in aquatic outlets have been acclimatized to freshwater conditions (with maybe a level teaspoonful of salt per 4.5 litres/1 gallon), so you should have no problems with them