Hey, the DP's are completly freshwater. They are best kept in herams, with two females for every one male. The males are distinguished by a black line down their belly. The females usually have "freckles" on their heads. They like heavily planted tanks to break up territories. I have some in a 29 (soon to be moved to a 46). They have sand substrate and both like and fake plants as well as driftwood pieces and a couple of flowerpots for coverage. I have 3 right now but will add more when they get moved. I also have an Ausellus puffer (or SA puffer) in with them, and a striped peacock eel. If you click on the link in my signature, there's a pic of it. It's the tank with the red substrate. PM me if you have any more questions!