Silver dat is brackish originally but can be kept in freshwater if it is acclimated to it. Takes beefheart and prepared foods heartily. Mine likes to frolic in the salt that I throw in the tank just right after a water change. Just make sure you don't have fish that does not like salt. That is a great pick up, especially that 7" Royal Panaque. That size normally sells here in Southern Cal for about $60.00 easy. Sometimes more. They love to eat driftwood.